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

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

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

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

Aeromonas hydrophila-associated skin lesions and septicaemia in a Nile crocodile (Crocodylus niloticus) : clinical communication

Aeromonas hydrophila is one of the most common bacteria associated with the aquatic environment. There are , however, limited data on A. hydrophila infection in crocodilians. The aim of this report is to describe a case of skin lesions and septicaemia associated with A. hydrophila in a Nile crocodile (Crocodylus niloticus). A captive male crocodile in the Zoological Park of Antalya (Turkey) was found dead without showing signs of any disease. Gross examination showed brown or red-spotted skin lesions of varying size. These lesions were mostly scattered over the abdomen and occasionally on the tail and feet. At necropsy, numerous white, multifocal and randomly distributed areas were seen on the liver. Gram-stained smears from skin and liver lesions showed Gram-negative bacilli arranged in clusters. Pure cultures of A. hydrophila were recovered from skin, internal organs and blood. Isolates were found to be susceptible to ceftiofur, amoxicillin + clavulanic acid, oxytetracycline, enrofloxacin, danofloxacin, neomycin, gentamicin, and lincomycin + neomycin. A pathogenicity test was performed using this isolate on 4 male 2-year-old New Zealand white rabbits. Local abscesses formed in 2 rabbits injected subcutaneously and the 2 that were injected intraperitoneally died as a result of septicaemia. In conclusion, this report has shown that A. hydrophila may cause skin lesions and even death due to septicaemia in crocodiles

Methicillin and aminoglycoside resistance in Staphylococcus aureus isolates from bovine mastitis and sequence analysis of their mecA genes

Although methicillin-resistant Staphylococcus aureus (MRSA) were generally isolated from human beings; these agents were recently isolated from various animal species. It has been shown that MRSA isolates are not only resistant to beta-lactam antibiotics, but can also be resistant to the other commonly used antibiotics. In this study, 18 phenotypic methicillin resistant S. aureus isolates from bovine mastitis cases were analyzed by PCR for the presence of mecA gene encoding methicillin resistance and aac(6')/aph(2aEuro(3)), aph(3')-IIIa and ant(4')-Ia genes encoding aminoglycoside resistance. Out of 18 S. aureus isolates (oxacillin MICs, a parts per thousand yen4 mu g/ml), 3 were positive for mecA gene. Only one from 3 mecA positive isolates was positive for genes encoding aminoglycoside-modifying enzymes and this isolate carried aac(6')/aph(2aEuro(3)) in combination with aph(3')-IIIa gene. The aph(3')-IIIa gene was detected in 3 isolates. These three isolates carrying the aminoglycoside-modifying enzyme genes were resistant to gentamicin, kanamycin and neomycin. The mecA gene of 3 MRSA isolates was sequenced. All three mecA genes of these isolates were identical to that found in human MRSA strains, except a one-base substitution at nucleotide position 757. From the data presented in this study, it can be concluded that MRSA isolated from bovine mastitis may be originated from human beings, but further studies are needed to investigate the possibility of zoonotic transfer of MRSA

Some viral and bacterial respiratory tract infections of dairy cattle during the summer season

In this research, dairy cattle with respiratory system problems that were brought to a private slaughterhouse in Burdur province were investigated for viral and bacterial infections present in the summer season. The blood samples were collected from 56 animals. The samples were tested for antibodies against bovine herpesvirus 1 (BoHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine parainfluenza virus 3 (BPIV-3) and bovine adenovirus 3 (BAV-3) by ELISA. Bacteriological cultivation was carried out from lung samples taken after cutting the same animals. The seropositivity rates which were determined for 5 viruses in cattle (BoHV- 1, BVDV, BRSV, BPIV-3 and BAV-3) were 7.14%, 50%, 94.64%, 94.64% and 82.14% respectively. The presence of antibodies against the viruses was as follows; 5.36% of cattle had antibodies against only one virus, 14.29% against two, 30.36% against three, 44.64% against four and 5.36% against five viruses. A total of 36 bacterial agents were isolated from 30 out of 56 lung samples. From the lung samples, only one bacterium was isolated from 39.3% (22/56) samples, and more than one bacterium from 14.3% (8/56). Escherichia coli, Staphylococcus aureus and Streptococcus spp. were detected as the most often isolated agents. Compared to bacteria, the rates of viral infections associated with Escherichia coli (BRSV+BPIV-3+BAV- 3+Escherichia coli; 8.92% and BRSV+BPIV-3+Escherichia coli; 5.35%) were higher. As a consequence, it was thought that primary agents which were the viruses and bacteria may have attended as secondary factors in respiratory tract infections of dairy cattle