Smrzavanje i otapanje uzoraka mlijeka prije nacjepljivanja na hranjivu podlogu poboljšava dijagnosticiranje stafilokoknog mastitisa u krava.

Diagnosis of staphylococcal mastitis cases may sometimes prove problematic due to the nature of the bacterium. Thus, in the present study, the effect of freezing and thawing bovine milk samples on the performance of standard cultures of staphylococcal mastitis was investigated to improve the diagnosis. Each of a total of 228 quarter milk samples from clinical and subclinical mastitis cases was plated on 7 % sheep blood agar directly, and after first being subjected to a process of freezing and thawing. The culture results from two methods were compared on the basis of Staphylococcus spp. positive udder counts and alteration in colony counts of the strains. In the first method, Staphylococcus spp. were isolated from 91 milk samples. In the second method, Staphylococcus spp. were isolated from an additional 11 milk samples that were negative in the first method. Staphylococcus spp. positive udder counts were found to be significantly different between the two methods. The changes in colony counts of the strains between the two methods were also found to be statistically significant in both clinical and subclinical mastitis cases, with the second method performing better. Consequently, these results indicate that a simple preculture step consisting of freezing and thawing milk samples has advantages for more sensitive diagnosis of staphylococcal mastitis in cattle milk.Zbog osobina uzročnika dijagnostika stafi lokoknog mastitisa ponekad može biti otežana. Radi poboljšanja dijagnostike u ovom je istraživanju istražen učinak smrzavanja i otapanja pretraživanih uzoraka mlijeka prije provođenja standardnog postupka uzgoja uzročnika. Svaki od 228 uzetih uzoraka mlijeka kod kliničkog i supkliničkog mastitisa bio je nacijepljen na krvni agar sa 7 % ovčje krvi izravno te nakon postupka smrzavanja i otapanja. Rezultati uzgoja obaju postupaka bili su uspoređeni na osnovi broja vimena pozitivnih na stafilokoke i broja poraslih bakterijskih kolonija. Kod izravnog nacjepljivanja Staphylococcus spp. bio je izdvojen iz 91 uzorka mlijeka. Nakon smrzavanja i otapanja Staphylococcus spp. bio je izdvojen iz još 11 uzoraka, koji su bili negativni kod izravnog nacjepljivanje bez prethodnoga smrzavanja i otapanja. Broj vimena pozitivnih na Staphylococcus spp. bio je statistički značajno različit između tih dvaju pretraživanih postupaka. Razlike u broju kolonija izolata bile su također statistički značajne između rabljenih postupaka kod dijagnosticiranja kliničkog i supkliničkog mastitisa. Boljim se pokazao postupak prethodnog smrzavanja i otapanja uzoraka mlijeka. Rezultati upućuju na zaključak da smrzavanje i otapanje uzoraka mlijeka prije nacjepljivanja na hranjivu podlogu ima prednosti s obzirom da se taj postupak pokazao osjetljivijim za dokazivanje stafilokoka kod pojave mastitisa u mliječnih krava

Extended-spectrum ß-lactamase and carbapenemaseproducing Aeromonas species in wild animals from Portugal

Aeromonas are Gram-negative, facultative-anaerobic, non-spore-forming, glucose-fermenting, oxidase- and catalase-positive rods (Martin-Carnahan and Joseph 2005). Apart from fish, which are widely reported hosts for Aeromonads, insects, crustaceans, reptiles, birds and mammals were also found to harbour Aeromonas species, both in healthy and disease state (Pearson and others 2000, Turutoglu and others 2005, Evangelista-Barreto and others 2006, Ceylan and others 2009). An increase in resistance levels of the genus, particularly to -lactam antimicrobial agents, has been observed not only in clinical isolates, but also in environmental strains (Saavedra and others 2004, 2007).C Dias was the recipient of grant SFRH/BD/90120/2012 from the Fundação para a Ciência e Tecnologia (FCT) under QREN – POPH- Potencial Humano, Tipologia 4.1 – Formação avançada da União Europeia, and strategic research project PEst-OE/AGR/ UI0772/2014

Mechanical and optical properties of silicon nitride thin films on glass

Optical thin films have been widely used in glass coating industry for various energy saving applications such as solar control and low emissivity glasses. However, handling and processing of these systems can lead into various mechanical defects decreasing its lifetime and optical performance. Therefore, understanding and control of the mechanical properties plays an important role in thin films production. Silicon nitride is one of the most commonly used materials in the optical systems. Its high refractive index and good mechanical properties provide different functionalities. It can be used as a buffer layer for tuning of the optical performance or as a topcoat for mechanical protection. Aim of this study is the investigation of mechanical and optical properties of silicon nitride thin films on soda-lime silicate glass. The films were deposited in in-line horizontal coater by DC magnetron reactive sputtering from Si (10% Al) target. Various argon and nitrogen flows, and sputter power were used in order to investigate the influence of the deposition parameters. Hardness and elastic modulus of silicon nitride films were measured by nanoindentation. Curvature method was used to obtain the residual stress values. Characterization of the optical properties was performed by spectroscopic ellipsometry

Antibiotic resistance in the environment, with particular reference to MRSA

The introduction of β-lactam antibiotics (penicillins and cephalosporins) in the 1940s and 1950s probably represents the most dramatic event in the battle against infection in human medicine. Even before widespread global use of penicillin, resistance was already recorded. E. coli producing a penicillinase was reported in Nature in 1940 (Abraham, 1940) and soon after a similar penicillinase was discovered in Staphylococcus aureus (Kirby, 1944). The appearance of these genes, so quickly after the discovery and before the widespread introduction of penicillin, clearly shows that the resistance genes pre-dated clinical use of the antibiotic itself

Investigations of Listeria Species in Milk and Silage Produced in Burdur Province

WOS: 000281800200016The aim of this study was to investigate the presence of Listeria species in the milk and silage samples obtained from fifteen different farms in Burdur. A total of 250 samples (silage and cow's milk obtained from animals fed and not fed with silage) were analyzed. L. monocytogenes was isolated in 6 (2.4%) out of the 250 samples. Five (6.66%) of the 75 silage samples and 1 (1.17%) of the 85 milk samples obtained from cows fed with silage were contaminated with L. monocytogenes, whereas no Listeria spp. were isolated from the 90 milk samples from cows not fed with silage. The isolation of L. monocytogenes from milk and silage samples in Burdur indicates that these products could create a serious risk to the public health

Characterization of Silicon Nitride Thin Films on Glass

The influence of process parameters on amorphous reactively sputtered silicon nitride thin films is reported in this study. The films were prepared with various argon and nitrogen flows, and sputter power in in-line horizontal coater by DC magnetron reactive sputtering from Si (10% Al) target. Refractive index and mechanical properties like residual stress, hardness and elastic modulus were studied. We show that process pressure has an important influence on mechanical properties of the sputtered film. On the other hand, the nitrogen content is the key factor for the optical properties of the films.</jats:p