MDR Salmonella enterica serovar Typhimurium ST34 carrying mcr-1 isolated from cases of bloodstream and intestinal infection in children in China.

OBJECTIVES: Children are vulnerable to Salmonella infection due to their immature immune system. Cases of infection with mcr-1-harbouring Salmonella in child inpatients have not been reported in China before. METHODS: Salmonella isolates from gastroenteritis and bacteraemia were screened using primers targeting mcr-1. Complete genome sequences of mcr-1-harbouring isolates were determined using the PacBio RS II platform. The transferability of mcr-1-harbouring plasmids was verified by conjugation. RESULTS: We investigated two mcr-1-carrying polymyxin-resistant Salmonella enterica serovar Typhimurium ST34 isolates, S61394 and S44712, from bloodstream and intestinal Salmonella infection of two child inpatients, respectively. Both isolates were non-susceptible to commonly used antibiotics for children that compromised the success of clinical treatment and infection control. The mcr-1-harbouring plasmids pLS61394-MCR and pLS44712-MCR (from S61394 and S44712, respectively) were both conjugative pHNSHP45-2-like IncHI2-type epidemic plasmids carrying multiple resistance genes. Compared with pHNSHP45-2, a ∼33 kb insertion region encoding Tn7 transposition protein and heavy metal resistance proteins was identified in pLS61394-MCR, which might enhance adaptation of bacteria carrying this plasmid to various ecological niches. The phylogenetic tree of worldwide mcr-harbouring Salmonella indicated a host preference of mcr and a worldwide and cross-sectoral prevalence of the mcr-positive Salmonella ST34 clone. CONCLUSIONS: To our knowledge, for the first time we report completed whole genomes of mcr-1-positive MDR Salmonella Typhimurium ST34 isolated from infected children in China, suggesting that improved surveillance is imperative for tackling the dissemination of mcr-harbouring MDR Salmonella Typhimurium ST34.

Epidemiology and Antimicrobial Susceptibility of Salmonella enterica Bloodstream Isolates Among Febrile Children in a Rural District in Northeastern Tanzania: A Cross-sectional Study.

BACKGROUND: Salmonella enterica including Salmonella Typhi and nontyphoidal Salmonella (NTS) are the predominant cause of community-acquired bloodstream infections in sub-Saharan Africa (sSA). Multiple-drug resistance and emerging fluoroquinolone resistance are of concern. Data on the age distribution of typhoid fever in sSA are scarce but essential for typhoid conjugate vaccine policy. We sought to describe Salmonella bloodstream infections, antimicrobial resistance, and age distribution at a rural district hospital in northeastern Tanzania. METHODS: From 2008 to 2016, febrile children or children with a history of fever aged 1 month to 5 years admitted to Korogwe District Hospital were enrolled. Demographic, clinical data and blood cultures were collected. Organisms were identified by conventional microbiological methods, and antimicrobial susceptibility test was done by disc diffusion. RESULTS: Of 4176 participants receiving blood cultures, 383 (9.2 %) yielded pathogens. Of pathogens, 171 (44.6%) were Salmonella enterica of which 129 (75.4%) were Salmonella Typhi, and 42 (24.6%) were NTS. The median (interquartile range age of participants was 13.1 (6.3-28.0) months for those with Salmonella Typhi and 11.5 (8.5-23.4) months for NTS. Of 129 Salmonella Typhi, 89 (89.9%) were resistant to amoxicillin, 85 (81.0%) to chloramphenicol, and 93 (92.1%) to trimethoprim-sulfamethoxazole compared with 22 (62.9%), 15 (39.4%), and 27 (79.4%), respectively, for NTS. Multidrug resistance was present in 68 (81.0%) of Salmonella Typhi and 12 (41.4%) of NTS. CONCLUSION: Salmonella Typhi was the leading cause of bloodstream infection among infants and young children <2 years of age admitted to Korogwe District Hospital. Multidrug resistance was common, highlighting a role for typhoid conjugate vaccine into routine infant vaccine schedules.

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.

Cytoplasmic Copper Detoxification in Salmonella Can Contribute to SodC Metalation but Is Dispensable during Systemic Infection.

Salmonella enterica serovar Typhimurium is a leading cause of foodborne disease worldwide. Severe infections result from the ability of S Typhimurium to survive within host immune cells, despite being exposed to various host antimicrobial factors. SodCI, a copper-zinc-cofactored superoxide dismutase, is required to defend against phagocytic superoxide. SodCII, an additional periplasmic superoxide dismutase, although produced during infection, does not function in the host. Previous studies suggested that CueP, a periplasmic copper binding protein, facilitates acquisition of copper by SodCII. CopA and GolT, both inner membrane ATPases that pump copper from the cytoplasm to the periplasm, are a source of copper for CueP. Using in vitro SOD assays, we found that SodCI can also utilize CueP to acquire copper. However, both SodCI and SodCII have a significant fraction of activity independent of CueP and cytoplasmic copper export. We utilized a series of mouse competition assays to address the in vivo role of CueP-mediated SodC activation. A copA golT cueP triple mutant was equally as competitive as the wild type, suggesting that sufficient SodCI is active to defend against phagocytic superoxide independent of CueP and cytoplasmic copper export. We also confirmed that a strain containing a modified SodCII, which is capable of complementing a sodCI deletion, was fully virulent in a copA golT cueP background competed against the wild type. These competitions also address the potential impact of cytoplasmic copper toxicity within the phagosome. Our data suggest that Salmonella does not encounter inhibitory concentrations of copper during systemic infection.IMPORTANCESalmonella is a leading cause of gastrointestinal disease worldwide. In severe cases, Salmonella can cause life-threatening systemic infections, particularly in very young children, the elderly, or people who are immunocompromised. To cause disease, Salmonella must survive the hostile environment inside host immune cells, a location in which most bacteria are killed. Our work examines how one particular metal, copper, is acquired by Salmonella to activate a protein important for survival within immune cells. At high levels, copper itself can inhibit Salmonella Using a strain of Salmonella that cannot detoxify intracellular copper, we also addressed the in vivo role of copper as an antimicrobial agent.

Clinical-associated characteristics and microbiological features of bloodstream nontyphoidal salmonella infection in adult patients receiving allogeneic hematopoietic stem cell transplantation.

Bloodstream nontyphoidal salmonella (NTS) infection is rare, but its associated characteristics and microbiological features in immunocompromised patients are worth paying attention to, particularly for those receiving allogeneic hematopoietic stem cell transplantation (SCT). No studies so far have analyzed post-transplant bloodstream NTS infection. Therefore, we reviewed 423 adult patients undergoing allogeneic hematopoietic SCT from 2003 to 2014. Nine out of four hundred twenty-three patients (2.13%) developed post-transplant bloodstream NTS infection, including two patients who had subsequent or combined metastatic infections. The median age at SCT was 35 years (interquartile range, 29-46) among the nine patients with bloodstream NTS infection. Male patients were predominant (78%). The median onset of bloodstream NTS infection was at 315 days after SCT (range, 207-629). Multivariate analysis revealed that extensive chronic graft-versus-host disease (GVHD) (OR 8.054, p = 0.003) and nonmyeloablative transplant conditioning (OR 4.604, p = 0.037) were significant associated characteristics for NTS infection. Currently, there are no published data analyzing and exploring post-transplant bloodstream NTS infections in adult allogeneic hematopoietic SCT. Our study determined the associated characteristics and microbiological features for this infection.

Salmonella colitis as an unusual cause of elevated serum lipase.

Authors and clinicians advocate lipase as the preferred serological test for the diagnosis for acute pancreatitis. While acute pancreatitis is among the differential diagnosis for elevated lipase levels, several other causes of elevated lipase levels have been identified including several reports Salmonella species as a causative agent. There also have been retrospective studies that have reported clinical pancreatitis associated with Salmonella infection. These studies concluded that clinical pancreatitis should be considered as a complication of Salmonella infections. However, Salmonella infections may induce elevated pancreatic enzyme levels without clinical pancreatitis or morphological pancreatic abnormalities through a variety of proposed mechanisms. The following is a case that describes a patient who developed Salmonella colitis and demonstrated elevated serum lipase levels without clinical pancreatitis.

Time Response of Oxidative/Nitrosative Stress and Inflammation in LPS-Induced Endotoxaemia-A Comparative Study of Mice and Rats.

Sepsis is a severe and multifactorial disease with a high mortality rate. It represents a strong inflammatory response to an infection and is associated with vascular inflammation and oxidative/nitrosative stress. Here, we studied the underlying time responses in the widely used lipopolysaccharide (LPS)-induced endotoxaemia model in mice and rats. LPS (10 mg/kg; from Salmonella Typhosa) was intraperitoneally injected into mice and rats. Animals of every species were divided into five groups and sacrificed at specific points in time (0, 3, 6, 9, 12 h). White blood cells (WBC) decreased significantly in both species after 3 h and partially recovered with time, whereas platelet decrease did not recover. Oxidative burst and iNOS-derived nitrosyl-iron hemoglobin (HbNO) increased with time (maxima at 9 or 12 h). Immune cell infiltration (CD68 and F4/80 content) showed an increase with time, which was supported by increased vascular mRNA expression of VCAM-1, P-selectin, IL-6 and TNF-α. We characterized the time responses of vascular inflammation and oxidative/nitrosative stress in LPS-induced endotoxaemic mice and rats. The results of this study will help to interpret and compare data from different animal species in LPS-induced endotoxaemia models for the identification of new drug targets.

Effects of Salmonella infection on hepatic damage following acute liver injury in rats.

BACKGROUND: Acute liver injury is a common clinical disorder associated with intestinal barrier injury and disturbance of intestinal microbiota. Probiotic supplementation has been reported to reduce liver injury; however, it is unclear whether enteropathogen infection exacerbates liver injury. The purpose of this study was to address this unanswered question using a rat model. METHODS: Oral supplementation with Salmonella enterica serovar enteritidis (S. enteritidis) was given to rats for 7 days. Different degrees of acute liver injury were then induced by intraperitoneal injection of D-galactosamine. The presence and extent of liver injury was assayed by measuring the concentrations of serum alanine aminotransferase, aspartate aminotransferase, and total bilirubin. Histology was used to observe liver tissue damage. Additionally, we measured the changes in plasma endotoxin, serum cytokines and bacterial translocation to clarify the mechanisms underlying intestinal microbiota associated liver injury. RESULTS: The levels of liver damage and endotoxin were significantly increased in the Salmonella infected rats with severe liver injury compared with the no infection rats with severe liver injury (P<0.01); The peyer's patch CD3+ T cell counts were increased significantly when the Salmonella infection with severe injury group was compared with the normal group (P<0.05). S. enteritidis pretreatment enhanced intestinal barrier impairment and bacterial translocation. CONCLUSIONS: Oral S. enteritidis administration exacerbates acute liver injury, especially when injury was severe. Major factors of the exacerbation include inflammatory and oxidative stress injuries induced by the translocated bacteria and associated endotoxins, as well as over-activation of the immune system in the intestine and liver.

The O-Antigen Capsule of Salmonella enterica Serovar Typhimurium Facilitates Serum Resistance and Surface Expression of FliC.

Group IV polysaccharide capsules are common in enteric bacteria and have more recently been described in nontyphoidal Salmonella species. Such capsules are known as O-antigen (O-Ag) capsules, due to their high degree of similarity to the O-Ag of the lipopolysaccharide (LPSO-Ag). Capsular polysaccharides are known virulence factors of many bacterial pathogens, facilitating evasion of immune recognition and systemic dissemination within the host. Previous studies on the O-Ag capsule of salmonellae have focused primarily on its role in bacterial surface attachment and chronic infection; however, the potential effects of the O-Ag capsule on acute pathogenesis have yet to be investigated. While much of the in vivo innate immune resistance of Salmonella enterica serovar Typhimurium is attributed to the high-molecular-weight LPS, we hypothesized that the O-Ag capsule may enhance this resistance by diminishing surface expression of pathogen-associated molecular patterns, such as flagella, and increasing resistance to host immune molecules. To test this hypothesis, O-Ag capsule-deficient mutants were constructed, and the loss of O-Ag capsular surface expression was confirmed through microscopy and immunoblotting. Loss of O-Ag capsule production did not alter bacterial growth or production of LPS. Western blot analysis and confocal microscopy revealed that O-Ag capsule-deficient mutants demonstrate reduced resistance to killing by human serum. Furthermore, O-Ag capsule-deficient mutants produced exclusively phase I flagellin (FliC). Although O-Ag capsule-deficient mutants did not exhibit reduced virulence in a murine model of acute infection, in vitro results indicate that the O-Ag capsule may function to modify the antigenic nature of the bacterial surface, warranting additional investigation of a potential role of the structure in pathogenesis.

Burden of Invasive Nontyphoidal Salmonella Disease in a Rural and Urban Site in Kenya, 2009-2014.

BACKGROUND: Invasive infections with nontyphoidal Salmonella (NTS) lead to bacteremia in children and adults and are an important cause of illness in Africa; however, few data on the burden of NTS bacteremia are available. We sought to determine the burden of invasive NTS disease in a rural and urban setting in Kenya. METHODS: We conducted the study in a population-based surveillance platform in a rural setting in western Kenya (Lwak), and an informal urban settlement in Nairobi (Kibera) from 2009 to 2014. We obtained blood culture specimens from participants presenting with acute lower respiratory tract illness or acute febrile illness to a designated outpatient facility in each site, or any hospital admission for a potentially infectious cause (rural site only). Incidence was calculated using a defined catchment population and adjusting for specimen collection and healthcare-seeking practices. RESULTS: A total of 12 683 and 9524 blood cultures were analyzed from Lwak and Kibera, respectively. Of these, 428 (3.4%) and 533 (5.6%) grew a pathogen; among those, 208 (48.6%) and 70 (13.1%) were positive for NTS in Lwak and Kibera, respectively. Overall, the adjusted incidence of invasive NTS disease was higher in Lwak (839.4 per 100,000 person-years of observation [PYO]) than in Kibera (202.5 per 100,000 PYO). The highest adjusted incidences were observed in children <5 years of age (Lwak 3914.3 per 100,000 PYO and Kibera 997.9 per 100,000 PYO). The highest adjusted annual incidence was 1927.3 per 100,000 PYO (in 2010) in Lwak and 220.5 per 100,000 PYO (in 2011) in Kibera; the lowest incidences were 303.3 and 62.5 per 100,000 PYO, respectively (in 2012). In both sites, invasive NTS disease incidence generally declined over the study period. CONCLUSIONS: We observed an extremely high burden of invasive NTS disease in a rural area of Kenya and a lesser, but still substantial, burden in an urban slum. Although the incidences in both sites declined during the study period, invasive NTS infections remain an important cause of morbidity in these settings, particularly among children <5 years old.

Invasive Salmonella Infections Among Children From Rural Mozambique, 2001-2014.

BACKGROUND: Invasive nontyphoidal Salmonella (iNTS) has emerged as a cause of bacteremia in African children and HIV-infected adults, which is associated with high mortality. Epidemiological data and burden of iNTS infections in resource-constrained settings are needed to better define preventive and curative strategies. METHODS: Blood and, if appropriate, cerebrospinal fluid, were collected from children <15 years of age with fever or severe disease admitted to the Manhiça District Hospital and cultured for NTS; isolates were then characterized. RESULTS: From January 2001 to December 2014, 41,668 of the 51,878 admitted children had a blood culture performed. Invasive NTS was isolated from 670 (1.6%) specimens collected from 41,668 patients; 69 (10.3% died). Salmonella enterica subspecies enterica serovar Typhi or Salmonella enterica subspecies enterica serovar Paratyphi A or C were only isolated in 14 (0.03%) patients. A total of 460 of 620 (74.2%) NTS isolates serotyped were Salmonella enterica subspecies enterica serovar Typhimurium (45% [116/258] of which were multilocus sequence type 313). The incidence of iNTS was 61.8 (95% confidence interval, 55.4-68.9) cases per 100,000 child-years, being highest among infants (217.7 cases/100,000 child-years). The incidence of iNTS declined significantly (P < .0001) over time, but the case fatality ratio remained constant at approximately 10%. Antimicrobial resistance of iNTS against most available antimicrobials has steadily increased, with a predominance of multidrug-resistant strains. CONCLUSIONS: The decreasing but still high incidence of iNTS, its high associated case fatality ratio, and the common detection of multidrug-resistant strains call for a need to improve treatment and prevention strategies for iNTS.

Timing of positive blood samples does not differentiate pathogens causing healthcare-associated from community-acquired bloodstream infections in children in England: a linked retrospective cohort study.

Paediatricians recognize that using the time-dependent community-acquired vs. hospital-acquired bloodstream infection (BSI) dichotomy to guide empirical treatment no longer distinguishes between causative pathogens due to the emergence of healthcare-associated BSIs. However, paediatric epidemiological evidence of the aetiology of BSIs in relation to hospital admission in England is lacking. For 12 common BSI-causing pathogens in England, timing of laboratory reports of positive paediatric (3 months to 5 years) bacterial blood isolates were linked to in-patient hospital data and plotted in relation to hospital admission. The majority (88·6%) of linked pathogens were isolated <2 days after hospital admission, including pathogens widely regarded as hospital acquired: Enterococcus spp. (67·2%) and Klebsiella spp. (88·9%). Neisseria meningitidis, Streptococcus pneumoniae, group A streptococcus and Salmonella spp. were unlikely to cause hospital-acquired BSI. Pathogens commonly associated with hospital-acquired BSI are being isolated <2 days after hospital admission alongside pathogens commonly associated with community-acquired BSI. We confirm that timing of blood samples alone does not differentiate between bacterial pathogens. Additional factors including clinical patient characteristics and healthcare contact should be considered to help predict the causative pathogen and guide empirical antibiotic therapy.

Identification of a common immune signature in murine and human systemic Salmonellosis.

Despite the importance of Salmonella infections in human and animal health, the target antigens of Salmonella-specific immunity remain poorly defined. We have previously shown evidence for antibody-mediating protection against invasive Salmonellosis in mice and African children. To generate an overview of antibody targeting in systemic Salmonellosis, a Salmonella proteomic array containing over 2,700 proteins was constructed and probed with immune sera from Salmonella-infected mice and humans. Analysis of multiple inbred mouse strains identified 117 antigens recognized by systemic antibody responses in murine Salmonellosis. Importantly, many of these antigens were independently identified as target antigens using sera from Malawian children with Salmonella bacteremia, validating the study of the murine model. Furthermore, vaccination with SseB, the most prominent antigenic target in Malawian children, provided mice with significant protection against Salmonella infection. Together, these data uncover an overlapping immune signature of disseminated Salmonellosis in mice and humans and provide a foundation for the generation of a protective subunit vaccine.

Pancreatic hyperenzymemia is associated with bacterial culture positivity, more severe and right-sided colitis.

BACKGROUND/AIM: Several studies reported pancreatic hyperenzymemia (PHE) related to acute colitis. However, there is no consensus on its clinical significance. This study was addressed to find the clinical significance of PHE in acute colitis. METHODS: Pancreatic hyperenzymemia was defined as abnormal increase in serum concentrations of the pancreatic enzymes by three times of normal upper range without definite pancreatic symptoms and evidence of pancreatitis at abdominal CT imaging of pancreatic disease. And clinical and laboratory and biologic parameters of PHE group and normal pancreatic enzymemia (NPE) group were compared. RESULTS: A total of 1,069 patients admitted to hospitals due to acute colitis were analyzed. Of these patients, 2.99 % (32/1,069) showed PHE. PHE group showed more severe symptoms and had longer hospital stays than the NPE group (12.15 vs. 4.59 days; P < 0.001). Multivariable analysis showed that right-sided colitis (OR 2.846; 95 % CI 1.122-7.224; P = 0.028) and culture positivity (OR 3.346; 95 % CI 1.119-10.008; P = 0.031) are associated with PHE during acute colitis. Also, PHE group was more common when a microorganism could be identified in the cultures (28.1 vs. 7.0 %; P = 0.003), especially blood culture. Among patients with positive cultures, Salmonella spp. had a positive correlation with the right-sided colitis and PHE (amylase P = 0.002; lipase P = 0.029), Salmonella serovar typhimurium (group B) was especially related to increased serum lipase but not to increased serum amylase (lipase; P = 0.041: amylase; P = 0.485). CONCLUSION: Pancreatic hyperenzymemia is associated with right-sided colitis, bacterial culture positivity, and severe acute colitis.

[The mode of differential diagnostic of and acute alcoholic gastroenteritis].

The study was carried out to develop mode of differential diagnostic of salmonella and acute alcoholic gastroenteritis on the basis of phospholipid specter of blood serum. The indicators of phospholipid fractions of blood serum were analyzed in 50 healthy persons, 50 patients with acute alcoholic gastroenteritis and 50 patients with salmonella gastroenteritis were analyzed. The relative content of following fractions of whole phospholipids were analyzed--total lysophospholipids, sphyngomiyelin, phosphatidcholine, phosphatidyletanolamin. The phospholipid spectrum of blood serum can be applied in differential diagnostic of salmonella gastroenteritis and acute alcoholic gastroenteritis. The disorders of metabolism of lipids under given pathological conditions have a multidirectional character. The salmonella gastroenteritis is characterized by decreasing of relative content of total lysophospholipids and increasing of phosphatidcholine as compared with standard conditions. The acute alcoholic gastroenteritis is characterized by increasing of relative content of total lysophospholipids and phosphatidcholine and decreasing of level of phosphatidcholine. The content of total Iysophospholipids in blood serum is lower on 35% or 30.0 mg% permits diagnosing acute alcoholic gastroenteritis. The content of phosphaltidcholine in blood serum higher than 40% or 50 mg% permits diagnosing salmonella gastroenteritis.

Redox proteomics of protein-bound methionine oxidation.

We here present a new method to measure the degree of protein-bound methionine sulfoxide formation at a proteome-wide scale. In human Jurkat cells that were stressed with hydrogen peroxide, over 2000 oxidation-sensitive methionines in more than 1600 different proteins were mapped and their extent of oxidation was quantified. Meta-analysis of the sequences surrounding the oxidized methionine residues revealed a high preference for neighboring polar residues. Using synthetic methionine sulfoxide containing peptides designed according to the observed sequence preferences in the oxidized Jurkat proteome, we discovered that the substrate specificity of the cellular methionine sulfoxide reductases is a major determinant for the steady-state of methionine oxidation. This was supported by a structural modeling of the MsrA catalytic center. Finally, we applied our method onto a serum proteome from a mouse sepsis model and identified 35 in vivo methionine oxidation events in 27 different proteins.

[Induction and protective properties of antibodies against muramyl peptides of gram-negative bacteria].

AIM: Characterize the role of humoral immune response in mechanisms of action of muramyl dipeptide immune stimulators. MATERIALS AND METHODS: Mice were immunized by a complex of muramyl peptides (CMP) obtained from Salmonella typhi peptidoglycan and consisting of 3 components: 1) N-acetyl-D-glucoasminyl-(beta1- > 4)-N-acetyl-D-muramoyl-L-alanyl-D-isoglutaminyl-meso-diaminopimelic acid (GMtri); 2) N-acetyl-D-glucosaminyl-(beta1- > 4)-N-acetyl-D-muramoyl-L-alanyl-D-isoglutaminyl-meso-diaminopimeloyl-D-alanine (GMtetra) and 3) GMtetra dimer (diGMtetra), in which monomeric residues of GMtetra are linked by an amid bond between carboxyl group of terminal D-alanine of one of GMtetra residues and omega-amino group of meso-diaminopimelic acid of the other GMtetra residue. RESULTS: Immunization resulted in a multifold increase of IgM, IgG1 and IgG2a titers against CMP. Antibodies were directed against the whole molecule of diGMtetra and did not recognize its fragments. Sera of mice immunized with CMP protected the mice from lethal infection with Gram-negative (S. typhimurium) but not Gram-positive (Staphylococcus aureus) microorganisms. CONCLUSION: Induction of protective antibodies may present a novel mechanism of action of muramyl dipeptide immune stimulators.

[Serum phospholipids in differential diagnostics of acute alcohol and salmonella gastroenteritis].

The aim of the study was to estimate the possibility of using the serum phospholipid spectrum for differential diagnostics of acute alcoholic and salmonella gastroenteritis. It included 50 patients and 50 healthy subjects. The following fractions were measured: total lipophospholipids (LPL), sphyngomyelin (SM), phosphatitylcholine, (PC) and phosphatidylethanolamine (PE). The serum phospholipid composition in patients of the two groups was significantly different. Salmonella gastroenteritis was characterized by reduced LPL and increased PC levels. Acute alcohol gastroenteritis was associated with elevated LPL, PE levels and reduced PC level. Relative LPL, PE levels in salmonella gastroenteritis were significantly higher and PC levels lower than in alcohol gastroenteritis. In the latter the LPL level was twice that in salmonella gastroenteritis whereas PC level was 1.5 times lower

Diagnostic performance of serum interleukin-6 and interleukin-10 levels and clinical predictors in children with rotavirus and norovirus gastroenteritis.

OBJECTIVES: Rotavirus and norovirus are the two most common causes of acute viral gastroenteritis in children. This study aimed to explore the association of serum interleukin-6 (IL-6) and interleukin-10 (IL-10) levels and the clinical features in children with rotavirus and norovirus gastroenteritis. METHODS: This prospective study enrolled 168 acute gastroenteritis patients admitted to a tertiary care center. Peripheral blood samples were collected for IL-6 and IL-10 assays within the first 72 h of illness. The diagnostic performance of clinical tests was estimated using the receiver operating characteristic (ROC) analysis. Binary logistic regression modeling was performed to examine the predictive variables. RESULTS: Serum IL-6 and IL-10 were measured in children with rotavirus infection (n=30), norovirus infection (n=25), Salmonella infection (n=26), and in 11 healthy controls. There were significant higher degrees of severity of illness and levels of IL-10 in the rotavirus group as compared to the norovirus group. The binary logistic regression analysis revealed that both the ANC and maximum body temperature (BT) were significant clinical predictors for discriminating rotavirus and norovirus gastroenteritis. The ROC curve to evaluate the accuracy of logistic regression model had an AUC of 0.847 (95% CI: 0.741-0.952, p<0.001). CONCLUSIONS: IL-10 shows a significant discriminating ability between rotavirus and norovirus infection. A model incorporating maximum BT and ANC can help pediatricians to distinguish between rotavirus and norovirus in children with a suspected viral gastroenteritis.

Characteristics of non-typhi Salmonella gastroenteritis associated with bacteremia in infants and young children.

PURPOSE: To characterize the clinical and laboratory manifestations of non-typhi Salmonella gastroenteritis associated with bacteremia in children less than 36 months old. METHODS: The study group included 17 patients, aged 2-34 months, with non-typhi Salmonella gastroenteritis and bacteremia, hospitalized in a tertiary pediatric medical center during the period 1995-2010. Clinical data were collected by medical chart review. Culture-related data were taken from the microbiology laboratory files. The results were compared with an assigned, age-matched, control group of 17 infants hospitalized with non-typhi Salmonella gastroenteritis without bacteremia. RESULTS: Eleven cases (65%) occurred during the summer season. All patients presented with diarrhea, usually mixed with blood or mucus (clinical dysentery 65%). All but one had a high-grade fever (average 39.5°C). Three patients (19%) experienced convulsions during the acute episode of gastroenteritis. None of the patients had been previously treated with antibiotics. The most prevalent Salmonella serotype identified in the stool and blood was group C. Toxic appearance and convulsions on admission were more common among children with non-typhi Salmonella bacteremia, as opposed to those with non-typhi Salmonella gastroenteritis alone. No other epidemiological or laboratory differences were found. CONCLUSIONS: Non-typhi Salmonella gastroenteritis poses a risk of bacteremia not only in infants younger than 3 months of age, but also in children younger than 36 months of age.