Antimicrobial Resistance, Genetic Diversity and Virulence Genes of Salmonella Typhimurium Isolated in Infant with Acute Diarrhea in Fuzhou, China, 2015 - 2017.

BACKGROUND: S. Typhimurium was the dominant serovar in an infant in Fuzhou, China. There have been few comprehensive studies on Salmonella typhimurium in infants in China. METHODS: We conducted a retrospective study on 30 Salmonella typhimurium from 3,200 fecal samples of infants with acute diarrhea from 2015 to 2017. Thirty S. Typhimurium strains were tested for antimicrobial susceptibility and characterized for virulence genes. Pulsed-field gel electrophoresis (PFGE) was also applied for comparison of genetic relatedness. RESULTS: All of the strains harbored misL, orfL, pipD, prgH, sifA, sopB, sitC, spiC, and invA genes. The other three gene distributions in the strains are different. Strains subtyped into 4 virulotypes (VP1-VP4), the most common virulence profile was VP3, accounting for 63.3% of the strains. The resistance to ciprofloxacin and ceftriaxone was 26.7%. The proportion of MDR isolates is approximately 90.0%. Sixteen different antimicrobial resistance patterns were observed and the most frequent resistance type was antibiotype 13 (resistance to streptomycin, tetracycline, amoxicillin), occurring in 43.3% of the isolates. Regarding PFGE, 30 isolates of S. Typhimurium showed genetic diversity, while no predominant PFGE patterns were observed in S. Typhimurium. Moreover, no correlation between virulence profiles or antibiotic patterns and PFGE clusters was observed. With one exception, VP1 which harbors pefA showed more diversity than the other virulence profiles among PFGE profiles. CONCLUSIONS: Our study provided valuable information on virulence gene content, antibiotic resistance, and genetic diversity of S. Typhimurium isolated from infant with acute diarrhea in Fuzhou, China.

Incidence of nontyphoidal Salmonella intestinal infections, active component, U.S. Armed Forces, 2007-2016.

During 2007-2016, there were 1,536 incident cases of nontyphoidal Salmonella infection among active component service members, with an overall crude incidence rate of 12.4 cases per 100,000 person-years (p-yrs). The overall rate for the period was higher among female service members than males. Service members aged 50 years or older and those aged 25-29 years had the highest rates of nontyphoidal Salmonella infection. Compared to their respective counterparts, overall rates were highest among non-Hispanic white service members, members of the Air Force, junior officers, recruits, and service members in healthcare occupations. Annual incidence rates were relatively stable during the first 9 years of the surveillance period. Rates peaked in 2016 at 15.9 cases per 100,000 p-yrs. The monthly distribution of the cumulative number of cases during the period showed a pattern of seasonality with a summer peak and the largest number of infections in July. During 2008-2016, a total of 132 cases were diagnosed in deployment settings, with an overall crude incidence rate of 12.6 cases per 100,000 p-yrs. Standard measures for the prevention of salmonellosis are reviewed.

Preventing Foodborne and Enteric Illnesses Among At-Risk Populations in the United States and Rhode Island.

One out of every six people in the United States is estimated to become sick each year from pathogens that can cause foodborne illness. The groups at greatest risk for serious illness, hospitalization, or death include young children, older adults, people with chronic conditions, and pregnant women. Such health disparities must be considered along with those disparities that may exist among racial and ethnic groups and among groups of varying socioeconomic status. We analyzed risk profiles for enteric disease using data from Rhode Island and the nation as a whole, exploring disparities among groups defined by demographic and health characteristics. As expected, disparities in the burden of enteric illnesses are not limited to racial or ethnic differences in disease burden, or in differences otherwise attributable to socioeconomic status. Age is an especially important determinant of risk, as is residential status. Other groups found to be especially vulnerable to foodborne and enteric illnesses in Rhode Island include pregnant women and those with certain health conditions (e.g., cancer, liver disease or immunosuppression). By understanding what groups are at increased risk, providers can more effectively counsel their patients to mitigate risk and effectively treat these conditions. [Full article available at http://rimed.org/rimedicaljournal-2016-11.asp].

The molecular epidemiological characteristics and genetic diversity of salmonella typhimurium in Guangdong, China, 2007-2011.

BACKGROUND: Salmonella enterica serovar Typhimurium is the most important serovar associated with human salmonellosis worldwide. Here we aimed to explore the molecular epidemiology and genetic characteristics of this serovar in Guangdong, China. METHODOLOGY: We evaluated the molecular epidemiology and genetic characteristics of 294 endemic Salmonella Typhimurium clinical isolates which were collected from 1977 to 2011 in Guangdong, China, and compared them with a global set of isolates of this serovar using epidemiological data and Multilocus Sequence Typing (MLST) analysis. PRINCIPAL FINDING: The 294 isolates were assigned to 13 Sequencing types (STs) by MLST, of which ST34 and ST19 were the most common in Guangdong. All the STs were further assigned to two eBurst Groups, eBG1 and eBG138. The eBG1 was the major group endemic in Guangdong. Nucleotide and amino acid variability were comparable for all seven MLST loci. Tajima's D test suggested positive selection in hisD and thrA genes (p<0.01), but positive selection was rejected for the five other genes (p>0.05). In addition, The Tajima's D test within each eBG using the global set of isolates showed positive selection in eBG1 and eBG138 (p<0.05), but was rejected in eBG243 (p>0.05). We also analyzed the phylogenetic structure of Salmonella Typhimurium from worldwide sources and found that certain STs are geographically restricted. ACSSuT was the predominant multidrug resistance pattern for this serovar. The resistant profiles ACSSuTTmNaG, ACSSuTTmNa and ACSuTTmNaG seem to be specific for ST34, and ASSuTNa for ST19. CONCLUSION: Here we presented a genotypic characterization of Salmonella Typhimurium isolates using MLST and found two major STs are endemic in Guangdong. Our analyses indicate that genetic selection may have shaped the Salmonella Typhimurium populations. However, further evaluation with additional isolates from various sources will be essential to reveal the scope of the epidemiological characteristics of Salmonella Typhimurium in Guangdong, China.

Caracterización fenotípica y genotípica de Salmonella Typhimurium variante 5- asociada a un brote de enfermedad transmitida por alimentos en el municipio de Paz de Río, Boyacá, 2010 / Phenotypic and genotypic characterization of Salmonella Typhimurium variant 5- isolates associated with an outbreak of food-borne disease in Paz de Rio, Boyacá, Colombia, in 2010

Introducción: Salmonella enterica serotipo Typhimurium variante 5- es un patógeno muy relacionado con animales, especialmente con palomas, y asociado en pocos casos con infecciones esporádicas en humanos. Sin embargo, los sistemas de vigilancia epidemiológica han permitido detectarla en brotes en humanos. Objetivo: caracterizar por técnicas fenotípicas y genotípicas los aislamientos de Salmonella Typhimurium variante 5- asociados a un brote de enfermedad transmitida por alimentos (ETA) en el municipio de Paz de Río, Boyacá, en el 2010. Materiales y métodos: doce aislamientos de Salmonella spp., fueron remitidos para confirmación bioquímica, identificación del serotipo y perfil de susceptibilidad antimicrobiana. Se analizaron genotípicamente por electroforesis en gel de campo pulsado (PFGE) con las enzimas Xbal y Blnl. Resultados: todos los aislamientos se confirmaron como Salmonella spp., y presentaron resistencia a tetraciclina y estreptomicina y sensibilidad a los demás antibióticos ensayados; 11/12 se identificaron como Salmonella Typhimurium variante 5- y mostraron en la PFGE el patrón COIN10.JPX.X01.0168 con la enzima XbaI y dos aislamientos de este mismo grupo se confirmaron con la enzima BlnI obteniendo el patrón de PFGE COIN10.JPX.A26.0002. El aislamiento restante se identificó como Salmonella Typhimurium con patrón de PFGE con la enzima Xbal COIN10.JPX.X01.0221. Conclusión: se reporta por primera vez en Colombia un brote de ETA asociado epidemiológicamente con aislamientos de Salmonella Typhimurium variante 5- que estuvieron relacionados fenotípica y genéticamente.

Introduction: Salmonella enterica serotype Typhimurium variant 5- is a pathogen closely related to animals, especially pigeons, which has been also associated in rare cases with sporadic infections in humans. However, epidemiological surveillance systems have enabled the detection of this variant in human outbreaks. Objective: To characterize by means of phenotypic and genotypic techniques the isolates of Salmonella Typhimurium variant 5- associated with an outbreak of food-borne disease in Paz de Rio, Boyacá, Colombia (2010), in order to establish their molecular relationships. Materials and methods: Twelve isolates of Salmonella spp., were analyzed by biochemical, serotyping and antimicrobial susceptibility tests. Pulsed-field gel electrophoresis (PFGE) with XbaI and Blnl enzymes was used to establish their molecular relationships. Results: All isolates were confirmed as Salmonella spp. They were resistant to tetracycline and streptomycin and sensitive to the rest of antibiotics tested. Eleven isolates were identified as Salmonella Typhimurium variant 5- and grouped in COIN10.JPX.X01.0168 pattern using the enzyme XbaI; two isolates in this group were confirmed using the enzyme BlnI with the COIN10. JPX.A26.0002 pattern. One isolate was identified as Salmonella Typhimurium with COIN10.JPX.X01.0221 pattern with the enzyme XbaI. Conclusion: This is the first outbreak in Colombia of foodborne illness epidemiologically associated with isolates of Salmonella Typhimurium variant 5 -, which were phenotypically and genetically related.

Patients with inhibitory and neutralizing auto-antibodies to interferon-γ resemble the sporadic adult-onset phenotype of Mendelian Susceptibility to Mycobacterial Disease (MSMD) lacking Bacille Calmette-Guerin (BCG)-induced diseases.

To recognize patients with inhibitory and neutralizing auto-antibodies to interferon-γ (AutoAbs-IFN-γ) presenting with the sporadic phenotype of Mendelian Susceptibility to Mycobacterial Disease (MSMD) mainly characterized by recurrent intracellular mycobacterium or/and salmonella infections, we comprehensively investigated IL12/23-IFN-γ signaling, candidate genetic sequencings or/and protein expressions of IL12RB1, IFNRG1, IL12p40, IFNRG2, STAT1, IKKA, NEMO, CYBB and IRF8 in four patients. Their serum was further titrated to detect AutoAbs-IFN-γ, for which the biological activity was assessed in Jurkat T cells. The patients mainly presented with recurrent non-tuberculous mycobacterium osteomyelitis and lymphadenopathy (Mycobacterium abscessus, chelonae and avium intracellular complex), and salmonella sepsis (S. enterica serogroup B, C2 and D). Additionally, Penicillium marneffei, varicella-zoster virus, and herpes simplex virus infections occurred. Inhibitory and neutralizing IFN-γ downstream signaling was elucidated in Jurkat cell lines as decreased MHC class I and phosphorylated STAT1 expression. Together with 24 patients from the PubMed search, the majority of the AutoAbs-IFN-γ patients were Asian (25/28). The most common involvement was lymph nodes (in 22/28), lungs (19/28) and bones (12/28). Mycobacterium avium complex (in 14) and chelonae (7) were the most common pathogens from 40 isolations. In contrast to those with the mild form of MSMD phenotype, AutoAbs-IFN-γ patients, in the absence of BCG-induced diseases, had a more persistent course and poor response to IFN-γ treatment. In conclusion, AutoAbs-IFN-γ patients may have a sporadic adult-onset MSMD phenotype in Asian regions endemic for mycobacterial infections.

Travel-associated salmonella and campylobacter gastroenteritis in England: estimation of under-ascertainment through national laboratory surveillance.

Increased international travel raises the importance of accurate surveillance of travel-associated gastroenteric pathogens to improve treatment and the investigation of cross-border outbreaks. This study found that 45% of Salmonella and 17% of Campylobacter infections in England were travel-associated, but only 29 and 3% of travel histories were accurately identified by national laboratory surveillance. More structured data collection forms and staff training may be needed to address this.

Invasive Salmonella infections in the United States, FoodNet, 1996-1999: incidence, serotype distribution, and outcome.

Invasive Salmonella infections are severe and can be life threatening. We analyzed population-based data collected during 1996-1999 by the Foodborne Diseases Active Surveillance Network (FoodNet), to determine the incidences, infecting serotypes, and outcomes of invasive Salmonella infection. We found that the mean annual incidence of invasive salmonellosis was 0.9 cases/100,000 population and was highest among infants (7.8 cases/100,000). The incidence was higher among men than women (1.2 vs. 0.7 cases/100,000; P<.001) and higher among blacks, Asians, and Hispanics than among whites (2.5, 2.0, and 1.3 cases/100,000 population, respectively, vs. 0.4 cases/100,000; all P<.001). Seventy-four percent of cases were caused by 8 Salmonella serotypes: Typhimurium, Typhi, Enteritidis, Heidelberg, Dublin, Paratyphi A, Choleraesuis, and Schwarzengrund. Of 540 persons with invasive infection, 386 (71%) were hospitalized and 29 (5%) died; 13 (45%) of the deaths were among persons aged > or =60 years. Invasive Salmonella infections are a substantial health problem in the United States and contribute to hospitalizations and deaths.

Salmonella and Shigella carriers among refugees from the middle east and Sri Lanka in Denmark.

One per cent of ten thousand refugees were asymptomatic carriers of Salmonella and Shigella species found by a differentiated health check programme at a Danish Red Cross arrival centre in Denmark 1985 and 1986. Six patients with typhoid fever and one with S. parathyphi-A septicaemia all fell ill within the first few weeks after arrival. A child of a chronic S. typhi carrier developed typhoid fever four months after arrival. Cases of sporadic and mild diarrhoea occurred due to Salmonella and Shigella species. The carriers were instructed in prophylactic, hygienic measures and no outbreaks developed. The health check system in this period seemed to be sufficient in relation to preventing outbreaks of infections caused by non-typhoid Salmonella and Shigella species. The relative cost-effectiveness of a more intensive S. typhi screening on arrival is questionable. The organization of health check systems should be reviewed regularly, as each refugee situation is different and will change in different periods.

Salmonella arizona infections in Latinos associated with rattlesnake folk medicine.

In 1987 two Los Angeles County (California) hospitals reported four Latino patients with serious Salmonella arizona (Salmonella subgroup 3) infections who gave a medical history of taking rattlesnake capsules prior to illness. Capsules supplied by the patients or household members grew Salmonella arizona. We reviewed surveillance data for this Salmonella species and conducted a case-control study to determine the magnitude of this public health problem. Eighteen (82 percent) of the 22 Latino cases in 1986 and 1987 who were questioned reported ingesting snake capsules compared to two (8 percent) of 24 matched Latino controls with non-subgroup 3 salmonellosis or shigellosis (matched pair odds ratio = 18.0, CI = 4.2, 76.3). An average of 18 cases per year of Salmonella arizona were reported in the county between 1980 and 1987. In this investigation the majority of S. arizona cases reporting snake capsule ingestion had underlying illnesses such as acquired immunodeficiency syndrome (AIDS), diabetes, arthritis, cancer. The capsules were obtained primarily from Tijuana, Mexico and from Los Angeles, California pharmacies in Latino neighborhoods. Despite publicity and attempts to remove the capsules from sale in California, Salmonella arizona cases associated with snake-capsule ingestion continue to occur.