The etiological structure of shigellosis in the former USSR--an indicator of the activity of the main routes of infection transmission]

The data on the etiological structure of Shigella infections in the USSR in 1988-1989 are presented. The study showed the dominating role of S. flexneri with S. sonnei also retaining great importance in Shigella infections. The process of the liquidation of S. dysenteriae and S. boydii infections began in some large cities. The domination of dysentery caused by S. flexneri and a high typhoid rate, particularly in Central Asia, were due to poor water supply of the population. The spread of dysentery caused by S. sonnei was completely independent of the water factor. The decisive role in the transmission of S. sonnei in infective doses was explained by decentralized milk supply.     

The etiological structure of acute intestinal infections in children in the Republic of Tajikistan]

The Republic of Tajikistan belongs to the territories, traditionally hyperendemic with respect to acute enteric diseases (AED). The problem of AED still remains topical in recent years, especially among child population. The study of the etiological structure of AED in children has made it possible to establish that more than 70% of these diseases are of infectious nature. The leading role in the etiological structure of these diseases belongs to Shigella infections (32.4%), enterovirus diarrhea (12.1%) and Escherichia infections (8.9%). No significant differences in the character of the etiological structure of AED in children of urban and rural areas have been detected with the exception of enterovirus diarrhea, found to occur 2.7 times more frequently on children of urban areas (15.9%) than in those of rural areas (5.8%). The ascertaining of the etiological structure of AED in Tajikistan will make it possible to essentially increase epidemiological surveillance on AED and render it more concrete.     

The etiological structure of acute intestinal infections caused by noncholera vibrios in the Volga delta

During summer months the proportion of acute enteric infections caused by non-cholera vibrios reaches was found to reach 11.4%. Their etiological factors were V. fluvialis (30.3%), V. parahaemolyticus (27.3%), V. costicola (21.2%) and V. damsela (21.2%). As revealed in this study, cases of infection in humans caused by vibrios, with the exception of V. costicola, were more closely linked with the contamination of water than that of fish (the correlation coefficients were equal, respectively, to 0.782 and 0.443). Suggestion was made that cases of human infections were caused not only by infective agents brought seafood, but also by vibrios inhabiting the Volga and contaminating fresh-water fish. The necessity of epidemiological surveillance on diseases caused by noncholera vibrios is substantiated.     

The definition of the forms of the epidemic process in intestinal infections]

A method for the identification of the forms of the epidemic process in dysentery (annual, seasonal and outbreak forms) has been worked out. The method is based on the calculation of the upper limits of annual and seasonal morbidity from the data on the period of several years with the use of the formulae of binomial distribution, serving as the mathematical model of alternative random values, such as morbidity. The comparison of actual morbidity for each year of the analyzed period with the upper limits of annual and seasonal morbidity helps identify the form of the epidemic process.     

The different electrophoretic forms of post gamma-globulin their antigenic identity and their structural variability.

Post gamma-globulin, first described as a constant component of protein of cerebrospinal fluid and urine from patients with tubular disorders has also been found in other biological fluids. Post gamma-globulin from a single individual always migrated as several bands after storage. Three electrophoretic forms, immunochemically identical, have been isolated by gel chromatography, preparative continuous flow electrophoresis and ion-exchange chromatography. Their molecular weight was found to be approximately between 11 000 to 12 000. No difference between the three forms could be detected. The N-terminal amino acids were found to be Lys, Arg and Leu respectively for the three forms of post gamma-globulin. The "slow" and "fast" forms of post gamma-globulin seemed to differ by elimination of small basic peptides or amino acids from the N-terminal end of the protein. No enzymatic activity of post gamma-globulin was found, but this requires further investigations.     

Correction of intestinal dysbacteriosis in elderly patients with the use of bifidobacterin introduced by different routes

The results of the correction of disturbances in intestinal microflora in elderly patients with the use of bifidumbacterin in the form of powder or suppositories are presented. The effectiveness of the rectal administration of bifidumbacterin (by microinjections through an enema or in suppositories) is shown in comparison with the oral administration of the preparation. The administration of bifidumbacterin in suppositories for 15 days resulted in decreased content of hemolytic Escherichia below the threshold of determination in all examined patients.     

The occurrence of Campylobacter subtypes in environmental reservoirs and potential transmission routes

AIM: To identify potential reservoirs and transmission routes of human pathogenic Campylobacter spp. METHODS AND RESULTS: An enrichment PCR method for the detection and identification of Campylobacter jejuni and/or Campylobacter coli in faecal, food and river water samples was applied to 1450 samples of 12 matrix types obtained from a defined geographical area. PCR-positive samples were cultured to yield isolates for typing, and the data for 616 C. jejuni isolates obtained. Serotyping and SmaI macrorestriction profiling using pulsed field gel electrophoresis revealed a high level of diversity within the isolates from each matrix. Campylobacter jejuni and C. coli subtypes indistinguishable from those obtained from human cases were detected in most of the matrices examined. No Campylobacter isolates were isolated from possum faeces. CONCLUSIONS: Ten of the 12 matrices examined may be involved in the transmission of human campylobacteriosis as they contained Campylobacter subtypes also isolated from clinical cases. SIGNIFICANCE AND IMPACT OF THE STUDY: Results indicate that, for this rural population, a range of potential transmission routes that could lead to campylobacteriosis exist. Their relative importance needs to be assessed from an exposure assessment standpoint.     

The preparation of biotinyl-epsilon-aminocaproylated forms of the vasoactive intestinal polypeptide (VIP) as probes for the VIP receptor.

Vasoactive intestinal polypeptide (VIP) was biotinyl-epsilon-aminocaproylated using sulfosuccinimidyl-6-(biotinamido) hexanoate thereby producing a series of products that were separated by high performance liquid chromatography (HPLC). Seven VIP-derivatives were isolated and the number and location of biotinyl-epsilon-aminocaproylation was determined by a combination of enzymatic degradation and plasma desorption mass spectrometry (PDMS). Receptor binding experiments with the VIP biotinyl-epsilon-aminocaproylated derivatives revealed IC50 values for the monobiotinyl-epsilon-aminocaproylated peptides that were 1.3-3.2 times higher than for natural VIP. All isolated biotinyl-epsilon-aminocaproylated derivatives possess VIP-like bioactivity as shown by an assay measuring pancreatic juice secretion in cat, VIP biotinyl-epsilon-aminocaproylated in position lysine being almost equipotent with natural VIP.     

The main difference between the repertoire of receptors of effector T-killers and their secondary precursors (memory cells)

Receptor repertoire analysis of in vivo induced secondary cytotoxic T lymphocyte precursors (pCTL-2) was performed, using the technique of their specific adherence to macrophage monolayers with subsequent elution of the adherent pCTL-2 and their activation by heat-killed donor stimulator cells. The capacity of anti-H-2Kb pCTL-2 receptors to contact H-2Kbm has been revealed only in a minor pCTL-2 component whose progenitors were able to lyse mutant bm1 target cells (TC). Unlike poor cross-reactivity of CTL descended from anti-Kb, pCTL-2 which were eluted from the donor monolayer, CTL-progenitors of anti-Kb pCTL-2 eluted from bm 1 or B10. A (4R) third-party monolayers lyse in equal quantities the donor TC and those third-party TC from which they have been eluted, but fail to lyse other TC. Enrichment of pCTL-2 eluted from bm 1 or B10. A (4R) monolayers is 6- or 12-fold lower, respectively, than after their elution from the donor monolayer. The findings indicate that anti-class I MHC pCTL-2 are separated into fractions, with their receptors being strongly specific (with high affinity) to the particular fragment of the same complex epitope without cross-reactivity to other fragments. These data differentiate pCTL-2 receptors from effector CTL ones which are homogenous in specificity to a whole (single) complex epitope with variable degree of complementarity. A cardinal distinction of receptor repertoire between CTL, pCTL-2 and suppressor T cells specific to the same class I MHC molecule and alteration of the active site during pCTL-2 differentiation have been suggested.     

The cell-mediated immune reaction in the cutaneous lesion of Chromoblastomycosis and their correlation with different clinical forms of the disease

Chromoblastomycosis is a fungal infection caused by dematiaceous fungi inducing skin lesions of difficult treatment and of frequent recurrence. The objective of the present investigation was to characterize cell-mediated tissue reactions in the skin in cases of Chromoblastomycosis using histopathology and immunocytochemistry methods and to correlate them with different clinical forms of Chromoblastomycosis. Biopsies from 19 patients were stained with HE and Giemsa, and serial sections were immunohistochemically stained using CD45RO, CD20, CD4, CD8, CD68, CD1a, CD34, IL4, IL10, TNF- and IFN- antibodies. A quantitative and semi quantitative analysis of the cell subsets and cytokines in the inflammatory infiltrates was performed by counting ten high-power fields (400×). The cutaneous lesion presented as verrucous plaque (n = 15) or erythematous atrophic plaque (n = 4). We observed two types of tissue reaction: A) a granulomatous reaction with a suppurative granuloma with several fungi cells in the cutaneous lesion presenting as verrucous plaque; B) a granulomatous reaction with a tuberculoid granuloma with few fungi cells in the cutaneous lesion presenting as atrophic plaque. The data obtained suggest that patients with lesion presented as verrucous plaque have a type Th2 immunological response, while patients with lesion presented as erythematous atrophic plaque have a type Th1 response.This revised version was published online in October 2005 with corrections to the Cover Date.     

Contact networks and transmission of an intestinal pathogen in bumble bee (Bombus impatiens) colonies

In socially living animals, individuals interact through complex networks of contact that may influence the spread of disease. Whereas traditional epidemiological models typically assume no social structure, network theory suggests that an individual’s location in the network determines its risk of infection. Empirical, especially experimental, studies of disease spread on networks are lacking, however, largely due to a shortage of amenable study systems. We used automated video-tracking to quantify networks of physical contact among individuals within colonies of the social bumble bee Bombus impatiens. We explored the effects of network structure on pathogen transmission in naturally and artificially infected hives. We show for the first time that contact network structure determines the spread of a contagious pathogen (Crithidia bombi) in social insect colonies. Differences in rates of infection among colonies resulted largely from differences in network density among hives. Within colonies, a bee’s rate of contact with infected nestmates emerged as the only significant predictor of infection risk. The activity of bees, in terms of their movement rates and division of labour (e.g., brood care, nest care, foraging), did not influence risk of infection. Our results suggest that contact networks may have an important influence on the transmission of pathogens in social insects and, possibly, other social animals.