Salmonella isolates from urine cultures: serotypes and antimicrobial resistance in hospital settings.

This study investigated the serotypes and antimicrobial resistance of Salmonella isolates in urine cultures from 38 hospitalized patients. Nine serotypes were detected, and a large proportion was Typhimurium and Enteritidis. The strains presented resistance to 11 different antibiotics. Thirteen isolates (11 from serotype Typhimurium) exhibited multidrug resistance.

Magnetism-Resolved Separation and Fluorescence Quantification for Near-Simultaneous Detection of Multiple Pathogens.

In the modern era of molecular evidence-based medicine and advanced biomedical technologies, the rapid, sensitive and specific assay of multiple pathogens is critical to, but largely absent from, clinical practice. Therefore, to improve the current ordinary separation and collection method, we report herein a strategy of magnetism-resolved separation and fluorescence quantification for near-simultaneous detection of multiple pathogens, followed by the direct antimicrobial susceptibility testing (AST). To accomplish this strategy, we utilized aptamer-modified fluorescent-magnetic multifunctional nanoprobes (apt-FMNPs). FMNPs with intriguing different magnetic responses and excellent fluorescence quality were first self-assembled based on metal coordination interaction using (3-mercaptopropyl) trimethoxysilane, magnetic γ-Fe2O3, and fluorescent quantum dots as matrix components. Then, aptamers, which specific to target pathogens of Escherichia coli O157:H7 ( E. coli) and Salmonella typhimurium ( S. typ), were conjugated with FMNPs to yield apt-FMNPs nanoprobes for multiple pathogens assay. Based on the discrepant magnetic response of pathogen@nanoprobes complex under the identical external magnetic field, the model bacteria were fished out by magnetic adsorption at different time points and subjected to fluorescence quantification with good linear ranges and detection limits within 1h. Multiple pathogens spiked in real samples were also effectively detected by the apt-FMNPs and sequentially fished out for AST assay, which showed similar results to that for pure pathogens. The apt-FMNPs-based strategy of near-simultaneous detection of multiple pathogens shows promise for the potential application in the diagnosis and treatment of pathogen-related infectious diseases.

Urinary Tract Infections Due to Nontyphoidal Salmonella.

BACKGROUND: We sought to establish the characteristics of symptomatic nontyphoidal Salmonella (NTS) urinary tract infection (UTI) without concomitant gastroenteritis (GE) as a separate clinical entity. MATERIALS AND METHODS: We conducted a retrospective cohort single-center study and reviewed all cases of NTS bacteriuria between 1995 and 2016. Patients were assigned to a group according to their clinical presentation, namely, symptomatic NTS UTI without GE, GE with NTS bacteriuria or isolated asymptomatic NTS bacteriuria. We compared the characteristics of patients in the NTS UTI group to those of the latter 2 groups. RESULTS: NTS bacteriuria was found in 77 patients, of which 61 had records available for review. Twenty-one patients (including 17 adults) presented with NTS UTI, 30 patients presented with features of GE with NTS bacteriuria and 10 patients had asymptomatic NTS bacteriuria. NTS UTI was not significantly associated with older age, male sex, diabetes, immunosuppressive states or urologic abnormalities. There was a significant difference in the proportion of patients with an underlying urologic malignancy in the NTS UTI group (4 of 17 patients [23.5%]) as compared to those in the other groups (0 of 24 patients), P = 0.023. CONCLUSIONS: A unique group of patients with symptomatic NTS UTI without GE was identified. A significant association with urologic malignancies was demonstrated in patients with NTS UTI compared to those with GE and NTS bacteriuria or asymptomatic NTS bacteriuria.

Systemic responses of BALB/c mice to Salmonella typhimurium infection.

Salmonella typhimurium is a bacterial pathogen that poses a great threat to humans and animals. In order to discover hosts' responses to S. typhimurium infection, we collected and analyzed biofluids and organ tissues from mice which had ingested S. typhimurium. We employed (1)H NMR spectroscopy coupled with multivariate data analysis and immunological techniques. The results indicate that infection leads to a severe impact on mice spleen and ileum, which are characterized by splenomegaly and edematous villi, respectively. We found that increased levels of itaconic acid were correlated with the presence of splenomegaly during infection and may play an important role in Salmonella-containing vacuole acidification. In addition, metabonomic analyses of urine displayed the development of salmonellosis in mice, which is characterized by dynamic changes in energy metabolism. Furthermore, we found that the presence of S. typhimurium activated an anti-oxidative response in infected mice. We also observed changes in the gut microbial co-metabolites (hippurate, TMAO, TMA, methylamine). This investigation sheds much needed light on the host-pathogen interactions of S. typhimurium, providing further information to deepen our understanding of the long co-evolution process between hosts and infective bacteria.

Urinary tract infection due to salmonella in an otherwise healthy child.

Salmonella species are a rare cause of urinary tract infection in children. They are associated with a high incidence of structural abnormalities or immunosuppressive status. We report the case of a healthy 7-year-old boy with pyelonephritis due to Salmonella group. He did not have a history of recent gastroenteritis.

Salmonella enterica serovar Minnesota urosepsis in a patient with Crohn's disease in the absence of recent or current gastrointestinal symptoms.

Salmonella enterica serovar Minnesota is a rarely isolated organism in clinical samples mainly grown from stool cultures. Sepsis due to Salmonella is known in severely immunocompromised patients, but so far urosepsis due to S. enterica serovar Minnesota has not been described. We report a case of a 31-year-old patient suffering from Crohn's disease treated with infliximab and azathioprine, in whom was implanted a double-J ureteric catheter for urolithiasis. The patient presented with urinary tract infection and severe sepsis. S. enterica serovar Minnesota was grown from urine and blood cultures. After empiric antimicrobial treatment with meropenem and vancomycin, treatment was changed to ceftriaxone. Antimicrobial treatment was continued for a total of 3 weeks without evidence of Salmonella recurrence on follow-up visits. Salmonella spp. rarely cause urinary tract infection and sepsis. However, in immunocompromised patients, non-typhoidal salmonellosis merits a thorough clinical and microbiological evaluation.

Development of carbapenem resistance during therapy for non-typhoid Salmonella infection.

Multidrug-resistant Salmonella infection is a global problem, and carbapenems may represent the last therapeutic choice. We report a case of infection caused by ceftriaxone-resistant and ciprofloxacin-resistant Salmonella enterica serotype Typhimurium. A bla(CMY-2) -containing Tn6092, located on a self-transferable IncI1 plasmid, was found in all isolates derived from the patient. During ertapenem treatment, the strain developed carbapenem resistance. Apart from the OmpD deficiency found in all isolates, the strain further developed OmpC deficiency through a single gene mutation, and became carbapenem-resistant. Salmonella appears to be very plastic in developing antimicrobial resistance. Care must be taken by physicians when treating multidrug-resistant Salmonella infection.

Epidemiological investigation of Salmonella enterica serovar Kedougou in Thailand.

OBJECTIVE: Salmonella enterica serovar Kedougou is among the top 10 serovars reported in northern Thailand. The objective of this study was to identify risk factors associated with Salmonella Kedougou infection in Thailand and to compare the molecular types and antimicrobial resistance with Salmonella Kedougou isolates of human origin from United States and of animal origin from the United Kingdom. METHODS: Data from 13,976 Salmonella infections of which 253 were Salmonella Kedougou collected in Thailand between 2002 and 2008 were analyzed by logistic regression. Antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE) were performed on selected Salmonella Kedougou strains causing infections in Thailand (n = 66), and compared to isolates from the United States (n = 5) and the United Kingdom (n = 20). RESULTS: Logistic analysis revealed season (hot/dry; p = 0.023), region (northern Thailand; p < 0.001), and specimen (stool; p < 0.001) as significant risk factors associated with Salmonella Kedougou infection compared to other nontyphoid Salmonella. Of the Salmonella Kedougou isolates of human origin, 84% exhibited resistance to at least three antimicrobial classes. Three strains recovered from human stool in Thailand were resistant to third-generation cephalosporins: two harbored bla(CTX-M-63) and one bla(CMY-2). PFGE revealed 45 unique clusters. Isolates obtained from humans in Thailand and the United States presented identical PFGE profiles suggesting a travel association, whereas the majority of the animal isolates from United Kingdom clustered separately. CONCLUSIONS: This study reveals Salmonella Kedougou as a major cause of human infections in northern Thailand especially during the hot period and suggests a global spread probably due to travel. The clonal types causing infections in humans differed from those observed in animals in United Kingdom, which suggests the absence of an epidemiological link and could suggest differences in virulence. The high frequency of antimicrobial resistance, including emergence of resistance to fluoroquinolones and third-generation cephalosporins, might pose problems for treatment of infections.

Salmonelosis extraintestinal: clínica, epidemiología y resistencia antimicrobiana / Salmonella extraintestinal infection: clinic features, epidemiology and antimicrobial resistance

Se evaluaron retrospectivamente las características clínicas de 59 pacientes con aislamientos extraintestinales de Salmonella enterica no Typhi y la resistencia antibiótica entre 1988 y 2004. En el 95% de los casos se conocieron las condiciones de base del huésped que consistieron en: enfermedad oncohematológica (15), lupus eritematoso sistémico (11), síndrome de inmuno deficiencia adquirida (10), pacientes internados en neonatología (8), colecistitis (4) y otras (7). Las formas clínicas halladas fueron: bacteriemias primarias (26), bacteriemias secundarias a gastroenteritis (15), artritis séptica (7), infección urinaria (12), infección intraabdominal (5), meningitis (1) y pericarditis (1). En 29 pacientes se aisló Salmonella enterica no Typhi en más de una localización. El 15,8% y el 21,0% de 59 aislamientos presentaron resistencia a cefalosporinas de 3ª generación y a ampicilina, respectivamente. Salmonella Agona causó un brote epidémico en la sala de cuidados intensivos de neonatología, aislándose de sangre en 5 pacientes y en uno también de LCR. Este serotipo fue multirresistente. Imipenem, trimetroprima-sulfometoxazol y ciprofloxacina fueron los antibióticos más activos (CIM 50: 0,5; 0,5 y 0,002 µg/mL, respectivamente).

The clinical and antimicrobial resistance of 59 patients with extraintestinal infection by nontyphi Salmonella was retrospectively evaluated from 1988 to 2004. In 95% of the patients there were underlying diseases, which included: oncohematologic disease (15), systemic lupus erythematosus (11), acquired immunodeficiency disease (AIDS) (10), patients of neonatal units (8), colecistitis (4), and other disorders (7). The clinical manifestation were primary bacteremias (26), bacteremias secondary to gastroenteritis (15), arthritis (7), urinary tract infections (12), abdominal infections (5), meningitis (1) and pericarditis (1). In 29 patients Salmonella enterica no Typhi was isolated in more than one site. Resistance to third generation cephalosporins was observed in 15,8 % of these isolates, and resistance to ampicillin in 21,0%. Salmonella Agona was isolated from an outbreak in neonatal ICU; the organism was recovered from blood samples of five neonates and in one patient also isolated from CSF. These isolates showed multiresistance. Imipenem, trimetoprim-sulfametoxazol and ciprofloxacin were the three most active antimicrobial agents (MIC 50: 0.5, 0.5 and 0.002 µg/mL, respectively).

Human multidrug-resistant Salmonella Newport infections, Wisconsin, 2003-2005.

We conducted a retrospective study of Salmonella Newport infections among Wisconsin residents during 2003-2005. Multidrug resistance prevalence was substantially greater in Wisconsin than elsewhere in the United States. Persons with multidrug-resistant infections were more likely than persons with susceptible infections to report exposure to cattle, farms, and unpasteurized milk.

dfrA25, a novel trimethoprim resistance gene from Salmonella Agona isolated from a human urine sample in Brazil.

OBJECTIVES: To describe a novel trimethoprim resistance gene, designated dfrA25, which was detected as a gene cassette within a class 1 integron in Salmonella Agona. METHODS: The gene was cloned into Escherichia coli MT102 and resistance to 10 different antimicrobial drugs was measured. A phylogenetic tree was constructed based on representative trimethoprim-resistance-mediating DfrA proteins retrieved from GenBank. Filter-mating experiments and Southern blots of plasmid preparations were performed with the donor and selected transconjugants. RESULTS AND CONCLUSIONS: dfrA25 encodes a dihydrofolate reductase of 157 amino acids with closest identity (85%) to dfrA5 dihydrofolate reductase. dfrA25 was located on a transferable plasmid (approximately 150 kb) that also harboured the tetracycline resistance gene tet(A).

Salmonella bacteriuria: an increasing entity in elderly women in the United States.

Salmonellosis is a major cause of gastroenteritis in the United States and can lead to septicaemia, and other extra-intestinal illness including urinary tract infections (UTIs). To examine trends in Salmonella bacteriuria in the United States, surveillance data from the National Salmonella Surveillance System from 1980 to the end of 1999 were reviewed. Overall, 17442 urinary Salmonella isolates were reported, representing 2% of all Salmonella isolates from a known source. This proportion increased from 2% during 1980--1984 to 4% during 1995--1999. The median age of persons from whom these isolates came was 51 years; 12,176 (70 %) were women. Compared to the last national survey conducted between 1968 and 1979, the rate of Salmonella bacteriuria increased among women, from 2.0 per million persons in 1980 to 3.7 in 1999; the highest rate occurring in women > or = 70 years. National reporting of Salmonella bacteriuria increased in absolute incidence and as a proportion of all Salmonella, especially in elderly women and may represent an increase in the incidence of Salmonella UTIs. Better understanding of the uropathogenicity of Salmonella serotypes may further clarify the mechanisms of Salmonella UTIs.

Transmission of Salmonella enterica serotype typhimurium DT104 to infants through mother's breast milk.

This study documents the first reported transmission of Salmonella enterica serotype Typhimurium definitive type 104 (DT104) to premature fraternal twins via their mother's breast milk. When premature twin neonates developed severe enteritis in the neonatal intensive care unit (NICU), stool samples and the mother's breast milk were cultured for the presence of Salmonella. Antibacterial susceptibility patterns were determined. Semiquantitative organism abundance data were retrospectively gathered on 54 stored breast milk samples collected on 34 different days using a rapid, real-time polymerase chain reaction (PCR) methodology (LightCycler PCR). Fecal samples from other infants in the NICU at that time were also tested. Pulsed-field gel electrophoresis (PFGE) was used to assess the genetic composition of the isolated organisms. The twins' neonatal stools and mother's breast milk cultures revealed a resistance pattern (R-type) to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline. LightCycler PCR analysis of sequential breast milk samples confirmed this to be the likely source of transmission. In the subsequent outbreak investigation, none of the NICU surveillance fecal samples proved positive for this organism. The genetic composition of organisms isolated from the maternal breast milk was indistinguishable from those isolated from neonatal specimens as determined by PFGE. Antibiotic susceptibility tests coupled with PFGE patterns suggested that these Salmonella isolates were DT104. Because the prevalence of DT104 infections is rising in the United States, neonatologists should be aware of breast milk as a potential mode of transmission.

Possible asymptomatic carrier of salmonella typhimurium in the preputium: a case report.

Salmonella infections lead to several clinical syndromes such as acute gastroenteritis and bacteremia. Less frequent manifestations are extraintestinal focal infections, including urinary tract infections. A 10-month-old boy was admitted to the hospital with recurrent urinary tract infections treated with antibiotics. Salmonella typhimurium was isolated from the urine samples obtained in urine bags. The organism was also grown from a suprapreputial swab, but was not grown in the suprapubic urine specimen. Renal ultrasonography, intravenous pyelography and voiding cystourethrogram were found normal. The patient was then circumcised, following with no uropathogens were isolated from the urine. It is believed that circumcision not only prevented further urinary tract infection and protected the case from becoming a carrier of Salmonella typhimurium, it also halted a possible spread of Salmonella infection to the general public.

Urinary tract infection caused by nontyphoidal Salmonella: report of 30 cases.

Thirty cases of nontyphoidal Salmonella bacteriuria were identified by review of cultures performed at the Mayo Clinic (Minn.) from 1985 to 1989 and at the Federal Public Health Laboratory Innsbruck (Austria) from 1979 to 1989. All patients had symptoms of an acute urinary tract infection (UTI). In 24 cases nontyphoidal Salmonella was the sole pathogen isolated. Only 1 patient presented with concomitant gastroenteritis and 2 had experienced episodes of diarrhea during the weeks before the UTI, but 15 patients had positive stool cultures in the absence of a gastrointestinal illness. Among all positive urine cultures at the Mayo Microbiology Laboratory, 0.015% were positive for nontyphoidal Salmonella; at the Federal Public Health Laboratory Innsbruck, 0.024% of organisms cultured from urine were nontyphoidal salmonellae. In the majority of our patients, Salmonella UTI did not differ clinically from UTI caused by other members of the Enterobacteriaceae; only in renal transplant recipients was the course of genitourinary salmonellosis more serious. While some urinary isolates of nontyphoidal Salmonella may be fecal contaminants, all 30 isolates recovered from urine during this study were considered to be the cause of symptomatic UTI.