Trends in the development of the epidemic process in salmonellosis caused by Salmonella typhimurium and Salmonella enteritidis

The dynamics and structure of the epidemic process of Salmonella infections among the population of Perm in 1983-1988 was studied and the results of evaluation of antibiotic resistance of the dominating Salmonella species analyzed. The study revealed that a decrease in salmonellosis morbidity caused by S. typhimurium was associated with a limited circulation of anthroponotic (antibiotic-resistant) variants of Salmonellae and a relative increase in the proportion of zoonotic (antibiotic-sensitive) strains. At the period of elevated morbidity this Salmonella infection affected mainly young children in cold months, whereas in recent years seasonal morbidity rises shifted to spring-summer and summer-autumn months, affecting older age groups of the population. The study also revealed that a rise in salmonellosis morbidity caused by S. enteritidis was due to increased circulation of zoonotic variants of Salmonellae. Changes in the epidemiological situation necessitate correction of the system of epidemiological surveillance on Salmonella infections with the emphasis on sanitation measures in stock-breeding farms with unfavorable epidemiological situation.     

A comparative analysis of the properties of bacteria in the genus Salmonella isolated from children in Latvia]

Since social and economic changes in Latvia in 1991 the incidence of salmonellosis dramatically increased: more than 500 pediatric cases are registered every year. Specification of the properties of the Salmonella strains isolated in Latvia was undertaken. The study demonstrated that acute salmonellosis in pediatric inpatients was mainly due to S.typhimurium (78 per cent) and only in 22 per cent of the patients it was due to S.enteritidis. All the S.typhimurium isolates showed high antibiotic resistance defined by specific extended spectrum beta-lactamase (CTX-M-5).     

Recurrent bacteraemia caused by different Salmonella species in a systemic lupus erythematosus patient

Non-typhoidal Salmonella infections are increasingly being encountered. Recurrent systemic salmonellosis has previously been reported in both immunocompromised and immunocompetent hosts. However, recurrent salmonella bacteraemia by different species of salmonella has rarely been described. We report a patient with systemic lupus erythematosus having Salmonella enteritidis and Salmonella typhimurium infections after ingesting raw eggs and vegetables. Multiple internal organs, including left knee joint, left ovary and bones, were involved. The patient recovered with a prolonged course of antibiotics. This case illustrates that recurrent systemic salmonellosis can be caused by different species of pathogens, especially in immunocompromised hosts. Detailed food history and education on food hygiene is essential in making the diagnosis and preventing recurrence. A prolonged course of antibiotics may be needed to manage these cases.     

Experimental study of the antibiotic activity of cefuroxime

The antimicrobial spectrum of cefuroxime, an antibiotic of the cephalosporin family was studied in vitro with respect to 11 species (16 strains) of gram-positive and gram-negative bacteria and in vivo on albino mice with experimental salmonellosis or pneumococcal infections. The bacteria were either test cultures or isolates from patients. The studies showed that cefuroxime had a wide antibacterial spectrum in vitro. It inhibited the growth of Staph. aureus, Str. pneumoniae, E. coli, Salm. typhimurium, Kl. pneumoniae, Bac. subtilis and had no effect on Ps. aeruginosa, Pr. vulgaris, M. tuberculosis and M. fortuitum. Cefuroxime had also a high bacteriostatic effect with respect to the experimental pneumococcal infection and a lower bacteriostatic effect with respect to the experimental salmonellosis infection.     

Analysis of plasmid profile of antibiotic-resistant Enterobacteriaceae circulating in hospitals

Certain pheno- and genotype properties of S. typhimurium and some other representatives of Enterobacteriaceae resistant to antimicrobial drugs were studied. The strains were isolated from children with salmonellosis within 4 months when an infection hospital was subjected to microbiological observation. It was shown that by their antibiotic resistance, phagovars and molecular weights of the plasmid DNas, the strains S. typhimurium were similar to those isolated during hospital infections. The conjugative plasmids responsible for antibiotic resistance in some strains did not differ in their molecular weights and antibiotic resistance markers. The strains S. typhimurium similar in their pheno- and genotype properties were isolated only from 2 patients which allowed one to consider it possible that the patients were infected by the strains of common genesis. Analysis of nonpathogenic representatives of Enterobacteriaceae isolated from the patients along with the S. typhimurium strains confirmed the fact that the patients were infected with the same pathogenic strain.     

Clinical and epidemiological description of acute intestinal infections in children of the lower Volga region

In accordance with the results of laboratory diagnostics, carried out by bacteriological, serological and PCR methods, the etiological structure of acute bacterial and viral intestinal infections, most frequently occurring in children of the Astrakhan region, is presented. An important role of viral diarrhea cases, prevailing among the total number of cases of intestinal infections in children, is emphasized. The data on the irregular distribution of morbidity by months, especially in viral intestinal infections and salmonellosis with the prevalent involvement of children aged up to 2 years into the epidemic process, are presented. Infections affect mainly children given artificial feeding, as well as those with complicated premorbid state and frequently having acute respiratory viral infections.     

Design of Multiepitope Vaccine Construct Against Non-typhoidal Salmonellosis and its Characterization Using Immunoinformatics Approach

International Journal of Peptide Research and Therapeutics - Non-typhoidal salmonellosis (NTS) is a food-borne zoonotic disease of human and veterinary importance. Besides enteric infections, most...     

Spread of salmonellosis in Moscow and the ways of its prophylaxis

The article deals with the results of the epidemiological analysis of the spread of salmonellosis in Moscow. During the last 15 years the proportion of Salmonella enteritidis was about 80% and more. After salmonellosis morbidity decreased to 19.9 per 100,000 of the population (the minimum level) in 1985 its sharp rise was noted. Morbidity rate increased from 31.7 in 1987 to 55.1 per 100,000 in 1988, then to 93.9 per 100,000 of the population in 1989 (the maximum level). In the subsequent years up to 1996 a decrease in morbidity rate was observed, but in 1997-2002 morbidity rate stabilized within 29.8-35.7 per 100,000 of the population without a perceptible tendency towards decrease. The sharp increase of the etiological role of S. enteritidis which led to a wide spread of Salmonella infections was caused by the "chicken-egg" factor of their transmission. High morbidity rate among children and adults, registered all the year round, is the consequence of the constant epidemic activity of this factor.     

Antibody avidity indices of the saliva and serum antibodies in salmonellosis patients

The avidity characteristics of salivary and serum antibodies have been determined in 179 salmonellosis patients by means of the indirect hemagglutination inhibition test. These investigation have shown that, in contrast to serum antibodies, no changes occur in the avidity of salivary antibodies in the course of the disease. This is due to the fact that secretory antibodies belong to IgA which have no tendency to ripening. The regularities thus established reflect the role of secretory and serum antibodies in the pathogenesis of Salmonella infections.     

Invasive Salmonellosis among Children Admitted to a Rural Tanzanian Hospital and a Comparison with Previous Studies

Background

The importance of invasive salmonellosis in African children is well recognized but there is inadequate information on these infections. We conducted a fever surveillance study in a Tanzanian rural hospital to estimate the case fraction of invasive salmonellosis among pediatric admissions, examine associations with common co-morbidities and describe its clinical features. We compared our main findings with those from previous studies among children in sub-Saharan Africa.

Methodology/Principal Findings

From 1 March 2008 to 28 Feb 2009, 1,502 children were enrolled into the study. We collected clinical information and blood for point of care tests, culture, and diagnosis of malaria and HIV. We analyzed the clinical features on admission and outcome by laboratory-confirmed diagnosis. Pathogenic bacteria were isolated from the blood of 156 (10%) children, of which 14 (9%) were S. typhi, 45 (29%) were NTS and 97 (62%) were other pathogenic bacteria. Invasive salmonellosis accounted for 59/156 (38%) bacteremic children. Children with typhoid fever were significantly older and presented with a longer duration of fever. NTS infections were significantly associated with prior antimalarial treatment, malarial complications and with a high risk for death.

Conclusions/Significance

Invasive salmonellosis, particularly NTS infection, is an important cause of febrile disease among hospitalized children in our rural Tanzanian setting. Previous studies showed considerable variation in the case fraction of S. typhi and NTS infections. Certain suggestive clinical features (such as older age and long duration of fever for typhoid whereas concomitant malaria, anemia, jaundice and hypoglycemia for NTS infection) may be used to distinguish invasive salmonellosis from other severe febrile illness.     

Use of loading doses of bifidumbacterin forte for treatment of patients with acute enteric infections

The clinical observation of patients with acute enteric infections (AEI), treated with loading doses of Bifidumbacterin forte during the first 2 days of the disease, was carried out. The preparation was shown to produce a positive effect on the course of AEI: salmonellosis, alimentary toxicoinfections, acute, dysentery. The early decrease of the manifestations of intoxication, pain syndrome, diarrhea, as well as the acceleration of convalescence in comparison with standard treatment, were noted. The most essential dynamics was registered in salmonellosis patients. The analysis of clinical results allowed to recommend the use of loading doses of Bifidumbacterin forte, a probiotic with high colonization potential to normalize the microbiocenosis of the intestine in AEI.     

A survey of laboratory animal disease in Kenya.

Diseases and infections diagnosed in laboratory mice, rats, guinea-pigs, golden hamsters and rabbits at the Veterinary Research Laboratory, Kabete, Kenya, are listed and discussed. Zoonoses encountered included salmonellosis and lymphocytic choriomeningitis. A number of traditionally recognised conditions were recorded but there were some notable omissions. The changing picture in laboratory animal science in East Africa is outlined and attention is drawn to the need for work on related diseases and infections.     

Results of an epidemiological study of familial foci of salmonellosis in the Western Urals

The study of 449 family foci of salmonellosis demonstrated the possibility of detecting cases of salmonellosis, not diagnosed by clinical and bacteriological methods, in the passive hemagglutination test. Such undetected Salmonella carriers, not observing the rules of personal hygiene, contributed to the contamination of household articles, foodstuffs and the environment. The formation of the family foci of salmonellosis was facilitated by the belated detection and hospitalization of salmonelloses cases, as well as by the inadequate observance of the rules for infant care and feeding.     

Pasteurisation and the control of milkborne infection in Britain.

Infections carried in milk, particularly salmonellosis and campylobacter enteritis, have continued to feature in Great Britain in recent years. Less commonly reported infections included an outbreak in 1984 in England due to Streptococcus zooepidemicus, in which 12 people, eight of whom died, were admitted to hospital. The implementation of legislation in 1983 requiring heat treatment of cows'' milk for sale to the public reduced the incidence of milkborne infection in Scotland compared with previous years and compared with England and Wales, where, without legislative control, outbreaks continue to occur. Until compulsory pasteurisation is introduced throughout Britain and dairy farming communities can be persuaded to drink only heat treated milk outbreaks of milkborne infection will continue.     

Immunomodulating properties of various microbes--representatives of normal intestinal microflora]

The impact of oral administration of heat-killed bifidobacteria, lactobacteria, enterococci and bacteroides on mouse resistance to experimental salmonellosis and content of immunoglobulin-synthesizing cells in the proper plate of the small intestine was studied. It was shown that the administration of the killed bifidobacteria, lactobacteria and enterococci increased the animal resistance to experimental salmonellosis infection and induced an increase in the content of immunoglobulin-synthesizing cells in the proper plate of the small intestine. The administration of the killed bacteroides had no such effect. Possible development of bacterial preparations with immunomodulating properties based on killed bifidobacteria, lactobacteria or enterococci is discussed.     

Specific antibodies bound to secretory IgA in the sera of patients with intestinal infections]

Specific IgA and sIgA antibodies were studied in the sera of patients suffering from various intestinal diseases (dysentery, salmonellosis, typhoid fever, chronic typhoid carrier state) and in the sera of healthy persons immunized by parenteral route with typhoid alcohol vaccine. The nature of antibodies was identified in Coombs' test, using monospecific antisera to alpha-chain and to the secretory component. IgA and sIgA antibodies were revealed most frequently in the sera of dysentery patients and of chronic typhoid carriers. No sIgA antibodies were found in the sera of subcutaneously immunized persons. The presence of specific sIgA antibodies in the serum reflects the participation of local immune mechanisms in the formation of systemic immunity in the intestinal infections.     

Metabolic transformation affected by specific Salmonella O antigen in the lymphocytes of salmonellosis patients

Metabolic transformation in the lymphocytes of salmonellosis patients, manifested by changes in the proportion of nucleic acids due to the stimulating action of Salmonella specific O antigen, was studied by the method of microspectral luminescent analysis. The level of single-helix nucleic acids in lymphocytes was shown to increase 6-8 hours after the stimulating action of specific O antigen, which was manifested by the increase of the alpha parameter from 0.21 to 0.68 in salmonellosis patients. This made it possible to confirm the diagnosis of salmonellosis in 92-95% of cases even at the early period of the disease when serodiagnosis could not yet be made.     

Occurrence of Helicobacter pylori specific antigens in diseases of gastrointestinal tract

The results of the immunophoretic analysis of H. pylori antigenic structure are presented. Along with H. pylori O-antigen, specific surface antigen of acidic nature, relatively thermolabile with characteristics similar to those of K-antigens, was detected. A diagnosticum based on the coagglutination test for the rapid detection of H. pylori specific antigens in the patients' biological fluids (coprofiltrate, saliva) by the noninvasive method was developed. The circulation mode of H. pylori in human body and its correlation with the clinical symptoms of the disease was shown. H. pylori antigens were very frequently detected (in 65 - 83% of cases) in patients with acute bacterial enteric infections: shigellosis, salmonellosis, yersiniosis, campylobacteriosis. The newly developed method seems to be promising for the rapid diagnosis of H. pylori associated infections, for the prolonged monitoring and evaluation of the effectiveness of antibacterial therapy.     

Prolonged incubation period of salmonellosis in an outbreak of Salmonella enteritidis infection

An outbreak of Salmonella enteritidis infections occurred in Otaru, Japan, in September 1997. A total of 143 cases of salmonellosis were reported to the local Public Health Center. In this outbreak, one case had a 214-hr incubation period. We investigated 5 isolates including this case by phage typing and pulsed-field gel electrophoresis (PFGE) to determine the genetic heterogeneity of S. enteritidis. Five isolates were phage typed as reacted, but did not conform (RDNC) with identical reaction patterns and had quite similar PFGE patterns. Thus, the prolonged incubation period may not be attributed to genetic heterogeneity of the organism but rather to other factors.     

Salmonella pathogenicity island 2

Systemic infections by Salmonella enterica, such as typhoid fever, are a significant threat to human health. Recent studies indicate that the function of a type III secretion system encoded by Salmonella Pathogenicity Island 2 (SPI2) is central for the ability of S. enterica to cause systemic infections and for intracellular pathogenesis. This review summarizes approaches leading to the identification of SPI2, the molecular genetics and evolution of SPI2, and the current understanding of the regulation of gene expression. Recent studies have indicated that SPI2 is used by intracellular Salmonella to actively modify functions of the host cells. The role of SPI2 during pathogenesis of salmonellosis and current models regarding function will be discussed.