Fenotypical characteristic of coagulase negative staphylococci isolated from patients hospitalized on burn ward and surgical ward

The aim of the study was to analysis of the adhesion factors of coagulase-negative staphylococci (CNS) to intravenous catheter: ability to adhesion, slime production, hydrophobicity of surface of cells and susceptibility to antibiotics. The researches heve been done on CNS strains isolated from cardiosurgical patients. Slime production ability was evaluated using plate method according to Christensen and Congo Red Agar method. Adherence of bacterial strains to intravenous catheter (polytetrafluoroethylene) in vitro was determined using the method of Richards. Hydrophobicity of surface of cells was determined on the basis of agregattion in (NH4)2SO4 Susceptibility to antibiotics was determined using the disc-diffusion method. Out of the analyzed strains 19% were labeled as slime producing in the plate method and 14% in the Congo red Agar method. 43% of analyzed strains were found to have TTC reduction of 3+, 19% of 2+ and 28% of 1+. Among these 10% of the assesed strains did not reduce TTC.     

Normal or stress-induced fibroblast senescence involves COX-2 activity

Cyclooxygenase-2 (COX-2) is an inducible enzyme of the prostaglandin biosynthesis pathway. It is involved in many stress responses, and its activity can produce oxidative damage, suggesting it could participate in senescence. In this study, COX-2 expression is shown to increase during senescence of normal human dermal or prostatic fibroblasts, and the ensuing prostaglandin E(2) (PGE(2)) production to increase about 10-fold. Enhancing this COX-2 activity by supplying exogenous arachidonic acid accelerates the occurrence of the major markers of senescence, cell-size increase, spreading, senescence-associated-beta-galactosidase (SA-beta-Gal) activity and growth plateau. Conversely, blocking this COX-2 activity with the specific inhibitor NS398 partially inhibited the occurrence of these markers. COX-2 expression and PGE(2) production are also increased about 10-fold during both NF-kappaB- or H(2)O(2)-induced senescence. Using NS398 or small interferent RNA specifically targeting COX-2 attenuated the appearance of the SA-beta-Gal activity and growth arrest in both stress situations. Taken together, these findings indicate that COX-2 is highly up-regulated during both normal and stress-induced fibroblast senescence and contributes to the establishment of the senescent characteristics.     

Mutagenicity on chlorination of products formed by ozonation of naphthoresorcinol in water

The mutagenicity of products formed by chlorination after ozonation of naphthoresorcinol in aqueous solution was assayed with Salmonella typhimurium strains TA98 and TA100 in the presence and absence of S9 mix from phenobarbital- and 5,6-benzoflavone-induced rat liver. Ozonated and subsequently chlorinated naphthoresorcinol was directly mutagenic, as was ozonated naphthoresorcinol, in both strains tested. The mutagenic activity at chlorination with 8 equivalents of chlorine per mole of naphthoresorcinol after ozonation was markedly higher than that at only ozonation. Of the identified ozonation products of naphthoresorcinol, muconic acid, after chlorination with 2 or 4 equivalents of chlorine per mole of the compound, induced direct mutagenicity against TA98 and TA100. The chlorination of glyoxal with 0.5 and 1 chlorine equivalents per mole of the compound was shown to produce direct mutagenicity toward TA98. The identification of the chlorination products of these compounds is also discussed.     

The effect of an experimental neoplastic disease on the flux of sodium and potassium ions across red blood cells and on the lipid composition of their membranes.

The erythrocytes from Morris Hepatoma 5123 bearing rats took up Na+ and K+ ions from the incubation medium and released Na+ into the extracellular space at lower rates than did erythrocytes from intact control rats. The lipid composition of erythrocytes membranes from the tumor-bearing rats differed from that of membranes from unaffected rats, showing increased contents of phospholipid phosphorus and a decreased content of cholesterol, resulting in decreased cholesterol:phospholipid molar ratios.     

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Identification of mouse selenomethionine α, γ-elimination enzyme

The purpose of this study was to identify the seleno-l-methionine (l-SeMet) α,γ-elimination enzyme that catalyzes l-SeMet to generate methylselenol (CH₃SeH), a notable intermediate for the metabolism of selenium compounds, in mammalian tissues. The enzyme purified from ICR mouse liver was separated by one-dimensional gel electrophoresis, and the specific band was subjected to in-gel trypsin digestion followed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometric analysis. In the peptide mass fingerprinting search, the mass numbers of 14 peptides produced by tryptic digestion of the enzyme were consistent with the theoretical mass numbers calculated from the amino acid sequence of murine cystathionine γ-lyase (E.C. 4.4.1.1). The peptide sequence tags search was also performed to obtain the amino acid sequence data of five tryptic peptides. These peptides were significantly identical to the partial amino acid sequences of cystathionine γ-lyase. This enzyme was clearly shown to catalyze the α, γ-elimination reaction of l-cystathionine by the enzymological research. The K _m value for the catalysis of l-cystathionine was 0.81 mM and V _max was. 0.0013 unit/mg protein. These results suggested that cystathionine γ-lyase catalyzes l-SeMet to generate CH₃SeH by its α,γ-elimination reaction.     

Does Intrinsic Disorder in Proteins Favor Their Interaction with Lipids?

Intrinsically disordered proteins (IDPs) are implicated in a range of human diseases, some of which are associated with the ability to bind to lipids. Although the presence of solvent‐exposed hydrophobic regions in IDPs should favor their interactions with low‐molecular‐weight hydrophobic/amphiphilic compounds, this hypothesis has not been systematically explored as of yet. In this study, the analysis of the DisProt database with regard to the presence of lipid‐binding IDPs (LBIDPs) reveals that they comprise, at least, 15% of DisProt entries. LBIDPs are classified into four groups by ligand type, functional categories, domain structure, and conformational state. 57% of LBIDPs are classified as ordered according to the CH‐CDF analysis, and 70% of LBIDPs possess lengths of disordered regions below 50%. To investigate the lipid‐binding properties of IDPs for which lipid binding is not reported, three proteins from different conformational groups are rationally selected. They all are shown to bind linoleic (LA) and oleic (OA) acids with capacities ranging from 9 to 34 LA/OA molecules per protein molecule. The association with LA/OA causes the formation of high‐molecular‐weight lipid–protein complexes. These findings suggest that lipid binding is common among IDPs, which can favor their involvement in lipid metabolism.     

Effect of exercise on glycogen level in muscles and liver in rats

The effect of exercise of glycogen level in skeletal muscles and liver was studied in Wistar rats. The previously untrained animals were subjected to one-time exercise in form of swimming in water at 32 degrees C for 10, 20 and 30 min. The glycogen level in the muscles (in g per 100 g of tissue) fell down during the first 10 minutes of the exercise by a mean value of 0.45 g. During the following 10 minutes the decrease was smaller amounting on the average to 0.1 g. After 30 min the glycogen level in the muscles was about 0.1 g/100 g of tissue. Respective falls of glycogen level in the liver were on the average 0.99 g and 0.40 g/100 g of tissue. After 30 min of exercise the glycogen level in the liver was 1.2 g/100 g of tissue. The fall of glycogen level in the muscles was similar at all times during exercise in all animals, but in the liver fairly significant differences were observed in the first 10 min between individual groups of rats. Later on during exercise the differences in the liver glycogen falls decreased.     

Epidemiological,clinical, and public health response characteristics of a large outbreak of diphtheria among the Rohingya population in Cox’s Bazar,Bangladesh, 2017 to 2019: A retrospective study

BackgroundUnrest in Myanmar in August 2017 resulted in the movement of over 700,000 Rohingya refugees to overcrowded camps in Cox’s Bazar, Bangladesh. A large outbreak of diphtheria subsequently began in this population.Methods and findingsData were collected during mass vaccination campaigns (MVCs), contact tracing activities, and from 9 Diphtheria Treatment Centers (DTCs) operated by national and international organizations. These data were used to describe the epidemiological and clinical features and the control measures to prevent transmission, during the first 2 years of the outbreak. Between November 10, 2017 and November 9, 2019, 7,064 cases were reported: 285 (4.0%) laboratory-confirmed, 3,610 (51.1%) probable, and 3,169 (44.9%) suspected cases. The crude attack rate was 51.5 cases per 10,000 person-years, and epidemic doubling time was 4.4 days (95% confidence interval [CI] 4.2–4.7) during the exponential growth phase. The median age was 10 years (range 0–85), and 3,126 (44.3%) were male. The typical symptoms were sore throat (93.5%), fever (86.0%), pseudomembrane (34.7%), and gross cervical lymphadenopathy (GCL; 30.6%). Diphtheria antitoxin (DAT) was administered to 1,062 (89.0%) out of 1,193 eligible patients, with adverse reactions following among 229 (21.6%). There were 45 deaths (case fatality ratio [CFR] 0.6%). Household contacts for 5,702 (80.7%) of 7,064 cases were successfully traced. A total of 41,452 contacts were identified, of whom 40,364 (97.4%) consented to begin chemoprophylaxis; adherence was 55.0% (N = 22,218) at 3-day follow-up. Unvaccinated household contacts were vaccinated with 3 doses (with 4-week interval), while a booster dose was administered if the primary vaccination schedule had been completed. The proportion of contacts vaccinated was 64.7% overall. Three MVC rounds were conducted, with administrative coverage varying between 88.5% and 110.4%. Pentavalent vaccine was administered to those aged 6 weeks to 6 years, while tetanus and diphtheria (Td) vaccine was administered to those aged 7 years and older. Lack of adequate diagnostic capacity to confirm cases was the main limitation, with a majority of cases unconfirmed and the proportion of true diphtheria cases unknown.ConclusionsTo our knowledge, this is the largest reported diphtheria outbreak in refugee settings. We observed that high population density, poor living conditions, and fast growth rate were associated with explosive expansion of the outbreak during the initial exponential growth phase. Three rounds of mass vaccinations targeting those aged 6 weeks to 14 years were associated with only modestly reduced transmission, and additional public health measures were necessary to end the outbreak. This outbreak has a long-lasting tail, with Rt oscillating at around 1 for an extended period. An adequate global DAT stockpile needs to be maintained. All populations must have access to health services and routine vaccination, and this access must be maintained during humanitarian crises.

Jonathan Polonsky and colleagues report on a diphtheria outbreak among Rohingya people in Cox’s Bazar, Bangladesh during 2017-19.