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Extra-intestinal manifestations of salmonella infections.

While salmonellosis is often considered to affect primarily the gastrointestinal tract, infection at other sites may occur, producing characteristic clinical syndromes. We reviewed cases from our institutions and the literature on focal manifestations of salmonella infections. In the past, most extra-intestinal salmonella infections were caused by S. choleraesuis; however, we found S. typhimurium to be the predominant serotype. The mortality rate for patients in our series was considerably lower than the rate described for focal infections in other reviews. This may in part be due to lower proportion of infections due to S. choleraesuis, improved microbiologic and diagnostic techniques, increased use of ampicillin, and improved surgical techniques. Salmonella endocarditis usually occurs in patients with preexisting heart disease. Unlike other salmonella infections, S. choleraesuis is the most frequent serotype. Salmonella endocarditis is often very destructive, with a fatality rate of 70%. Nonvalvular (mural) endocarditis occurs in one-fourth of patients and survival has not been reported. While antibiotic therapy should be tried initially, if response is not prompt the clinician should look for an associated site of infection (intra- or extra-cardiac abscess), which will often require surgery. Salmonella pericarditis often presents with cardiac or pulmonary symptoms, but typical signs of pericardial disease (pulsus paradoxus, friction rub) or characteristic electrocardiographic changes (low voltage, elevated ST segments) are uncommon. Early diagnosis, before infection involves other areas of the heart, is crucial for survival. In addition to antibiotic therapy, pericardiocentesis or pericardiectomy is required. Salmonella may infect the peripheral or visceral arteries, but the abdominal aorta is the most frequent site of vascular infection. Most patients are men over age 50 with preexisting atherosclerosis of the aorta who do not have a previous history of gastroenteritis. About one-fourth of patients have associated lumbar osteomyelitis. No patients have been reported to survive with medical therapy alone. Specific guidelines for surgical removal of infected aneurysms have been proposed and these (in addition to increased use of ampicillin) may be responsible for higher survival rates in recent years. Due to the high incidence of relapses, postoperative blood cultures should be done routinely. Arterial infection should be considered in any elderly patient with salmonella bacteremia especially with prolonged fever or bacteremia after an "adequate course" of antibiotic therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

The relationship between infecting dose and severity of disease in reported outbreaks of Salmonella infections.

The relationship between size of the infecting dose and severity of the resulting disease has been investigated for salmonella infections by reanalysis of data within epidemics for 32 outbreaks, and comparing data between outbreaks for 68 typhoid epidemics and 49 food-poisoning outbreaks due to salmonellas. Attack rate, incubation period, amount of infected food consumed and type of vehicle are used as proxy measures of infecting dose, while case fatality rates for typhoid and case hospitalization rates for food poisoning salmonellas were used to assess severity. Limitations of the data are discussed. Both unweighted and logit analysis models are used. There is no evidence for a dose-severity relationship for Salmonella typhi, but evidence of a correlation between dose and severity is available from within-epidemic or between-epidemic analysis, or both, for Salmonella typhimurium, S. enteritidis, S. infantis, S. newport, and S. thompson. The presence of such a relationship affects the way in which control interventions should be assessed.

Disease Outbreaks↗

Salmonella infections in a cancer center.

Data concerning 40 patients hospitalized in a cancer center and Salmonella infection were analyzed. Hematological malignancy was present in 24 patients (60%) and solid tumor in 14 patients (35%). Among the predisposing factors, antineoplastic chemotherapy was the most frequent (60%) followed by antacid use (47.5%), corticosteroids (37.5%), granulocytopenia below 500 neutrophils/microliters (15%), surgery (10%) and splenectomy (2.5%). Bacteremia was the most frequent clinical syndrome accounting for 42.5% of the patients. Focal infection, enteritis and carrier state accounted for the remaining 30%, 20% and 7.5% respectively. Salmonella typhimurium and S. dublin represented 65% of the isolates, with clear association between serotype dublin and bacteremia. All S. dublin isolates were resistant to chloramphenicol. Among dublin and typhimurium serotypes, 20% the isolates were resistant to the traditional antibiotics used in salmonellosis (ampicillin, chloramphenicol, cotrimoxazole). All strains were susceptible in vitro to cephalosporins. The frequency of relapse was 15% and the overall mortality (within 30 days) attributed to Salmonella infection was 15%.

Adolescent↗

Isolation of human faecal bifidobacteria which reduce signs of Salmonella infection when orogastrically dosed to mice.

AIMS: The aim of the study was to isolate human bifidobacteria that inhibit growth of Salmonella typhimurium in vitro, and provide protection against Salmonella infection in mice. METHODS AND RESULTS: A total of 92 micro-organisms, which displayed antagonist activity against Salm. typhimurium in vitro, were isolated from human faecal material. Based on their Gram stain status, cultures were pooled and tested for anti-Salmonella activity. The Gram-variable group was the most active. From that group, three bifidobacteria (Laftitrade markB22, B74 and B97) individually showed good pathogen inhibition in vivo. CONCLUSION: Oral administration of certain human bifidobacteria provides protection against Salmonella infection in mice. SIGNIFICANCE AND IMPACT OF THE STUDY: These results indicate that certain bifidobacteria may be used as a prophylaxis for reduced incidence and severity of Salmonella infections.

Animals↗

Inhibition of bacterial adhesion and salmonella infection in BALB/c mice by sialyloligosaccharides and their derivatives from chicken egg yolk.

The effects of an egg-yolk-derived sialyloligosaccharide (YDS), asialo-YDS, and a sialylglycopeptide of YDS (SGP) on bacterial adhesion to intestinal epithelial cells and on Salmonella infection in BALB/c mice were examined. YDS, its derivative asialo-YDS, and SGP strongly inhibited the binding of Salmonella enteritidis but not E. coli K-88 to a human epithelial cell line, Caco-2. In a Salmonella infection experiment using BALB/c mice, oral administration of these reagents effectively prevented the bacteria from proliferating in spleen, as well as preventing lethality. An experiment using radioactive SGP orally administered to mice revealed that the compound was absorbed from the intestine into blood and eliminated via urine within 8 h. However, these reagents did not influence the production of TNF-alpha or NO. in culture macrophages. The results suggest that they inhibit Salmonella infection not by activating macrophages but by inhibiting the entry of bacteria through the gut, suggesting that YDS and its derivatives are useful for preventing Salmonella infection when ingested continuously.

Animals↗

[Characteristics of the antigen-binding properties of lymphocytes in experimental Salmonella infection].

The data on the count of antigen-binding lymphocytes in the blood and lymphoid organs of mice in the course of Salmonella infection are presented. The reaction used for their detection is specific. Antigen-binding lymphocytes detected in mice in Salmonella infection belong to T- and B-cell populations and carry surface receptors belonging to IgA and IgM. Study of antigen-binding lymphocytes 1-20 hours after infection may be helpful in the specific diagnosis of Salmonella infections.

Animals↗

The intracellular nature of Salmonella infection during the early stages of mouse typhoid.

In mouse enteric fever (typhoid) infection with S. typhimurium, the bacteria appear to grow intracellularly, and at least during the early phase of infection they are in splenic PMNs rather than macrophages. Inflammation caused by salmonella infection and other infections, such as MHV, results in inflammatory responses that enhance resistance to salmonella infection. At least in the case of MHV, this effect is most pronounced on the rate of salmonella growth. Since the effects of the Ity locus on salmonella growth rate are readily seen during the first few days of infection, when salmonella are primarily within PMNs, the Ity locus is able to mediate its effect on salmonella pathogenesis in PMNs in vivo. Whether or not macrophages play a predominant role in salmonella pathogenesis later in infection is not yet known.

Animals↗

[Salmonella infections in Kinshasa: the species involved and sensitivity to antibiotics].

292 Salmonella strains were isolated between 1986-1988 in the bacteriological unit of the Cliniques Universitaires de Kinshasa (Zaïre). One hundred of these strains were isolated from pediatric samples. The most frequent strains were S typhi, S enteritidis and S typhimurium. S typhi strains were sensitive to all antibiotics tested. The other salmonella serotypes had an increasing resistance to several antibiotics especially ampicillin, streptomycin, tetracyclin and kanamycin. A significant decline was observed with chloramphenicol and sulfamethoxazol-trimetoprim. Stool-isolated strains from children were found to be resistant to all antibiotics in common use in 5/6 cases. In systemic Salmonella infection, treatment with chloramphenicol or sulfamethoxazole-trimetoprim plus gentamycin is probably preferable to any other antibiotic recommended for Salmonella infection.

Child↗

[Salmonella enterica serotypes and Salmonella infections: a multicenter study covering ten provinces in Turkey].

In order to find the distinctive features of Salmonellae and Salmonella infections in Turkey, 620 Salmonellae strains, isolated from various clinical samples (481 stool, 108 blood, 12 urine, 3 bone marrow, 3 cerebrospinal fluid, 9 pus, and one from each of the bile, pleural fluid, wound, catheter samples) in 13 clinical microbiology laboratories of 10 provinces in Turkey (Ankara, Antalya, Bursa, Edirne, Eskişehir, Istanbul, Izmir, Kayseri, Konya and Trabzon) between July 1, 2000 and June 30, 2002, were serotyped. Among the patients 43% were female, 57% were male, 63.2% were from outpatient clinics and 36.8% were hospitalized patients. Seventy eight percent of the patients had gastroenteritis, 10.7% had septicemia/local infection, 9.8% had typhoid/paratyphoid fever and 1.5% were carriers. Incidence of gastroenteritis was higher in 0-5 years age group (p<0.001). Of the 620 Salmonella enterica isolates, 47.7% were S. Enteritidis, 34.7% S. Typhimurium, 6% S. Paratyphi B, 2.9% S. Typhi, 0.2% S. paratyphi A, 6.1% serogroup C1, and 2.4% serogroup C2. S. Enteritidis was the most common serotype in all provinces except for Kayseri, where S. Typhimurium was found to be the most common serotype (68.2%). Overall, the most frequently isolated serotype was S. Enteritidis, also being the most common serotype in stool and blood cultures. During the surveillance period two outbreaks have occurred, the first one by S. Enteritidis strains in Edirne, and the second one by S. Typhimurium strains in Kayseri. As a result, Salmonella infections are still a common health problem in Turkey, and active surveillance of Salmonella infections has vital importance.

Adolescent↗

Predominant activation and expansion of V gamma 9-bearing gamma delta T cells in vivo as well as in vitro in Salmonella infection.

Gamma delta T cell receptor-positive cells (gamma delta T cells) have recently been implicated to play a role in the protection against infectious pathogens. Serial studies on gamma delta T cells in 14 patients with salmonella infection have revealed that the proportions of gamma delta T cells (mean +/- SD: 17.9 +/- 13.2%) in salmonella infection were significantly increased (P less than 0.01) compared with 35 normal controls (5.0 +/- 2.6%) and 13 patients with other bacterial infections (4.0 +/- 1.4%). Expansion of gamma delta T cells was more prominent in the systemic form (28.9 +/- 10.8%) than in the gastroenteritis form (10.5 +/- 7.9%) of salmonella infection (P less than 0.01). Most in vivo-expanded gamma delta T cells expressed V gamma 9 gene product. Increased activated (HLA-DR+) T cells were observed in all the six patients with the systemic form and four of the seven with gastroenteritis form. Especially in the six with systemic form, gamma delta T cell activation was significantly higher than alpha beta T cell activation at the early stage of illness (P less than 0.01). When peripheral blood lymphocytes from normal individuals were cultured with live salmonella, gamma delta T cells were preferentially activated and expanded and most of them expressed V gamma 9. Purified gamma delta T cells also responded to live salmonella in vitro. The present study suggests that human gamma delta T cells play a role in the protection against salmonella infection in vivo.

Adolescent↗

Clinical review of nontyphoid Salmonella infections from 1991 to 1999 in a Danish county.

To determine outcomes of nontyphoid Salmonella infections, we reviewed all 3328 cases of infection registered in a large Danish county from 1991 to 1999. The hospitalization rate was 27% among patients <5 years old, 22% among patients 5-59 years old, and 54% among patients > or =60 years old; complications were present in 7% and extraintestinal disease in 4% of patients. We conclude that nontyphoid Salmonella infections may frequently cause severe disease even among patients without predisposing conditions.

Adolescent↗

Immunosuppression induced by Salmonella infection is correlated with augmentation of interleukin-2 receptor alpha chain expression in murine splenic lymphocytes.

In a previous study, we observed that the suppression of T-cell proliferation induced by Salmonella cell-free extract was associated with augmentation of IL-2 receptor (IL-2R) alpha chain expression. In this study, we also observed this kind of augmentation of IL-2R alpha in Salmonella-infected mice. Phytohaemagglutinin (PHA)-stimulated proliferation of murine spleen cells was significantly suppressed when the mice were infected with Salmonella typhimurium. However, expression of the alpha chain but not the beta chain of IL-2R in lymphocytes was augmented by the infection. Analysis of the IL-2R-positive cell-population showed that the augmentation of IL-2R alpha was not specific to certain cell subpopulations. Furthermore, the inhibition of PHA-stimulated murine spleen cell proliferation and the augmentation of IL-2R alpha expression induced by the infection in lymphocytes was completely reversed by treatment with anti-interferon-gamma monoclonal antibody (anti-IFN-gamma Ab). These results suggest that the suppression of T-cell proliferation induced by Salmonella infection was associated with augmentation of IL-2R alpha expression in an IFN-gamma production-dependent manner in the same way as the suppression of T-cell proliferation induced by Salmonella cell-free extract.

Animals↗

Direct costs associated with a nosocomial outbreak of Salmonella infection: an ounce of prevention is worth a pound of cure.

BACKGROUND: Nosocomial outbreaks of Salmonella infections in Australia are an infrequent but significant source of morbidity and mortality. Such an outbreak results in direct, measurable expenses for acute care management, as well as numerous indirect (and less quantifiable) costs to those affected, the hospital, and the wider community. This article describes the significant direct costs incurred as a result of a nosocomial outbreak of Salmonella infection involving patients and staff. METHOD: Information on costs incurred by the hospital was gathered from a number of sources. The data were grouped into 4 sections (medical costs, investigative costs, lost productivity costs, and miscellaneous) with use of an existing tool for calculating the economic impact of foodborne illness. RESULTS: The outbreak cost the hospital more than AU $120, 000. (US $95,000). This amount is independent of more substantial indirect costs. CONCLUSION: Salmonella infections are preventable. Measures to aid the prevention of costly outbreaks of nosocomial salmonellosis, although available, require an investment of both time and money. We suggest that dedication of limited resources toward such preventive strategies as education is a practical and cost-effective option for health care facilities.

Cross Infection↗

Effect of the mouse Nramp1 genotype on the expression of IFN-gamma gene in early response to Salmonella infection.

The early interferon-gamma (IFN-gamma) response after Salmonella infection was compared in resistant and susceptible congenic mice strains differing by the allele of Nramp1. IFN-gamma gene expression in vivo was studied by quantitative reverse transcription-PCR performed from the spleen of mice challenged by Salmonella either in multiplication or in resting phase. The spleen colonisation by Salmonella in vivo was investigated and was shown to be identical in a genetically defined host, whatever the initial phase of the bacteria. However, the bacterial load of the spleen was significantly reduced in Nramp1(r) (resistant) mice compared to Nramp1(s) (susceptible) mice. The background level of IFN-gamma mRNA was higher in the spleen of resistant mice than in the susceptible mice, before infection. Interestingly, the early upregulation of IFN-gamma gene transcription, which was observed after infection with Salmonella, was reproducibly delayed in susceptible mice compared to resistant mice. Finally, the kinetics of the host IFN-gamma response seems to be Nramp1 dependent. Resistant mice present the advantage of being more prompt to express this anti-infectious cytokine gene than susceptible mice in response to Salmonella infection.

Animals↗

Increased synovial endothelium binding and transendothelial migration of mononuclear cells during Salmonella infection.

OBJECTIVE: To investigate the adhesion and extravasation capacity of peripheral blood mononuclear cells (PBMC) and the transport of bacterial antigens within these cells during Salmonella infection. METHODS: Thirteen patients who were part of 2 outbreaks of Salmonella enteritidis infection were included in this study. The capacity of PBMC from these patients to bind to vascular endothelium in inflamed synovium was tested using a Stamper-Woodruff-type frozen-section assay. The same cells were studied for the presence of Salmonella antigens by immunofluorescence staining. The transendothelial migration of mononuclear cells containing Salmonella or its components through unstimulated endothelial cell layer was quantified. RESULTS: The capacity of PBMC to adhere to synovial vessels was significantly increased during Salmonella infection (P=0.0003). Monocytes had a transiently high adhesive state between 2 and 5 weeks after the patients had eaten the contaminated food. The cells containing Salmonella antigens were concentrated in the transmigrated population. CONCLUSION: During acute Salmonella infection the increased binding of PBMC to vascular endothelium in inflamed synovium and enhanced transmigration of PBMC containing Salmonella may be the key factors leading to transport of bacterial antigens through the endothelial barrier and initiation of arthritis in susceptible individuals.

Adult↗

[Salmonella infections in the county of Frederiksborg during the period 1983-1988].

During the years 1983 to 1988, a marked increase in the number of Salmonella infections notified to the Medical Officer of health in Frederiksborg was observed. The epidemiology of Salmonella infections has altered decisively during the past 5-10 years. The number has increased drastically and this increase is due particularly to increase in the number of isolated sporadic cases. The primary cause of the increasing number of infections is increasing contamination of foodstuffs with Salmonella. Improved hygiene in the food industry is essential if the number of infections is to be reduced. Children are frequently infected by direct or indirect contact. Salmonella infections are, therefore, a problem in day institutions and in day care homes. Contact infection may be prevented by improved hygiene and quarantine for children with infectious diarrhoea. Symptom-free excretors, on the other hand, do not present any particular risk for infection and should not be excluded from institutions. Children may excrete bacteria for several months and quarantine based on positive faeces cultures may have considerable social consequences.

Adolescent↗