1 Department of Microbiology and Parasitology, Medical Faculty, University of Rijeka, B. Branchetta 20, 51000 Rijeka, Croatia
2 Department of Microbiology and Immunology, University of Melbourne, ...Parkville, Victoria 3010, Australia
Correspondence Ivana Gobin ivanagobin{at}yahoo.co.uk
Received October 22, 2008
Accepted February 12, 2009
This study established an experimental model of replicative Legionella longbeachae infection in A/J mice. The animals were infected by intratracheal inoculation of 10 3 –10 9 c.f.u. L. longbeachae serogroup 1 (USA clinical isolates D4968, D4969 and D4973). The inocula of 10 9 , 10 8 , 10 7 and 10 6 c.f.u. of all tested L. longbeachae serogroup 1 isolates were lethal for A/J mice. Inoculation of 10 5 c.f.u. L. longbeachae caused death in 90 % of the animals within 5 days, whilst inoculation of 10 4 c.f.u. caused sporadic death of mice. All animals that received 10 3 c.f.u. bacteria developed acute lower respiratory disease, but were able to clear Legionella from the lungs within 3 weeks. The kinetics of bacterial growth in the lungs was independent of inoculum size and reached a growth peak about 3 logarithms above the initial inoculum at 72 h after inoculation. The most prominent histological changes in the lungs were observed at 48–72 h after inoculation in the form of a focal, neutrophil-dominant, peribronchiolar infiltration. The inflammatory process did not progress towards the interstitial or alveolar spaces. Immunohistological analyses revealed L. longbeachae serogroup 1 during the early phase of infection near the bronchiolar epithelia and later co-localized with inflammatory cells. BALB/c and C57BL/6 mice strains were also susceptible to infection with all L. longbeachae serogroup 1 strains tested and very similar changes were observed in the lungs of infected animals. These results underline the infection potential of L. longbeachae serogroup 1, which is associated with high morbidity and lethality in mice.
Adhesion of the most common dental biofilm bacteria to alloys used in orthodontics in relation to surface characteristics was analyzed. Streptococcus mutans (S. mutans), Streptococcus oralis (S. ...oralis), Veillonella parvula (V. parvula), and Aggregatibacter actinomycetemcomitans (A. actynomicetemcomitans) were incubated for 4 h with nickel-titanium (NiTi) and stainless-steel (SS) wires. The surface roughness and free energy of the alloys, as well as the hydrophobicity of the alloys and bacteria, were assessed. NiTi had higher surface free energy and rougher (p<0.001) and more hydrophilic surfaces than SS (p<0.001). The hydrophobic properties of the bacteria decreased in the following order: V. parvula>S. oralis>S. mutans>A. actynomicetemcomitans. Bacterial adhesion generally increased over time, though this pattern was influenced by the type of alloy and the bacteria present (p<0.001). In a multiple linear regression, the principal predictor of adhesion was bacterial hydrophobicity (p<0.001), followed by time (p<0.001); alloy surface characteristics had a low influence.
Legionella pneumophila je gram-negativna bakterija čije je prirodno stanište voda, uključujući rijeke, jezera i potoke. L. pneumophila je uzročnik pontiačke groznice i legionarske bolesti, a ...kontaminirani distribucijski sustavi za vodu i ovlaživači zraka samo su neki od izvora infekcije. Unatoč provođenju protuepidemijskih mjera, sve je češća pojava legioneloza, stoga je potrebno razviti nove metode za uklanjanje legionele iz vode. Jedan od pristupa je protumikrobna fotodinamička terapija koja uključuje zajedničko djelovanje fotosenzibilizatora, molekularnog kisika i vidljivog svjetla određene valne duljine u svrhu produkcije singletnog kisika i kisikovih reaktivnih vrsta koji ubijaju mikrobnu stanicu. U ovom su radu određivane minimalne inhibitorne i minimalne baktericidne koncentracije različitih porfirina na L. pneumophila u bujonu dilucijskom metodom. Korišteno je crveno svjetlo ukupne doze 24 J cm-2, a osvjetljavanje je trajalo 10 minuta. Najjači antibakterijski učinak utvrđen je kod amfipatskog porfirina i potrebna su daljnja istraživanja o djelotvornosti ovih spojeva i primjene fotodinamičke terapije u inaktivaciji legionele u vodi.
Učinjen je pregled recentne literature u svrhu opisivanja najnovijih saznanja o etiologiji, simptomatologiji i metodama liječenja, prognozi liječenja febrilnih konvulzija. Opisuje se učestalost ...nastanka febrilnih konvulzija u dječjoj populaciji u Općoj Bolnici Dubrovnik, i to u dvogodišnjem razdoblju. Podatci su prikupljeni retrospektivno uvidom u medicinsku dokumentaciju, tj. učinjen je uvid u povijesti povijest bolesti kod djece hospitalizirane na dječjem odjelu OB Dubrovnik
u razdoblju 2013.–2014. godine.
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