Listeria je patogen prenosiv hranom i predstavlja veliku opasnost za ljudsko zdravlje. Teški su simptomi praćeni visokom stopom mortaliteta većinom prouzročeni L. monocytogenes. Bez obzira na politiku nulte tolerancije, rod Listeria je još uvijek prisutan u sirovim proizvodima i proizvodima spremnim za konzumiranje, predstavljajući veliku opasnost za zdravlje ljudi. Za sada još u bliskoj budućnosti ne postoje studije o kontaminaciji hrane vrstama Listeria u Bosni i Hercegovini. Ovim istraživanjem htjeli smo dobiti osnovne podatke o količini kontaminiranosti hrane ovim patogenom. U studiji je analizirano ukupno 238 uzoraka hrane, pri čemu su u 105 uzorka bile različite vrste sirove hrane te 133 uzorka hrane spremne za konzumaciju (gotove hrane). Od ukupno 238 uzoraka, 18 uzoraka je bilo pozitivno na Listeria vrste. Nakon izolacije i detekcije, konfirmacija pozitivnih izolata Listeria spp. je provedena pomoću biokemijskog kita API® Listeria.

Motivation/Background: positive staphylococci (CPS) are common contaminants of raw milk. Before it is used, various heat treatments are applied to destroy microorganisms, inactivate enzymes and improve technological properties and concentration of dry matter of milk. This work aimed to determine the influence of commonly used heat treatments in diary on presence and number CPS in raw milk from Bosnia and Herzegovina area and to affirm whether there is a difference in efficacy between different treatments. Method: Using the standard method, 40 samples of raw milk from farms were inoculated for counting the initial number of CPS in raw milk. Samples were then exposed to heat treatments in vapor sterilizer and CPS number was counted using the same standard method. Results: Applied treatments included heat treatments at: 68 °C/40 s, 70 °C/15 s, 72 °C/without holding, 63 °C/30 min and 72 °C/15 s. CPS presence was detected in all tested samples of raw milk in numbers ranging from 2,82 to 5,32, with an average of 4,30, calculated as log10 /ml. Conclusions: Raw milk samples collected in the field initially registered a high CPS number. The applied heat treatments were effective to a large extent. The initial CPS count of milk seems to be the most important factor determining the number of CPS after heat treatments as well as traits of the strains.

Introduction: Legionella bacteria are ubiquitous microorganisms mostly found in artificial water environments, especially those which produce aerosol, such as swimming pools, saunas, and spas. Development of Legionella depends on several factors, including water temperature and chlorine. The aim of this study was to evaluate the occurrence of Legionella spp. to the temperature and free residual chlorine in tap water, water from fountains, swimming pools, cooling and heating systems. Methods: We collected 238 samples of water taken from different places and analyzed the presence of Legionella spp. by BAS EN ISO 11731-2:2009 - Water quality – Detection and enumeration of Legionella - Part 2: A direct membrane filtration method for waters with low bacterial counts, as samples were the waters with low expectancy of bacterial contamination compared to the temperature and free residual chlorine. The X2 test was used to show statistical significance. Results: Legionella spp. was detected in 18.62% of tap water and in 8.82% samples of water taken from fountains, swimming pools, and cooling and heating systems. The highest number of positive samples were detected in waters with the temperature higher than 20°C and lower than 50°C. The highest number of positive samples were reported by the concentration of free residual chlorine lower than 0.2 mg/l. The X2 test showed a statistically significant difference between positive and negative results for the presence of Legionella spp. among three groups of water samples. Conclusion: The research has shown a connection between environmental factors and the presence of Legionella spp. in the water systems of public and tourist facilities.

Introduction: Water can support the growth of different microorganisms which may result in contamination. Therefore, the microbiological examination is required for testing the hygienic probity of water. In the study of microbial composition of untreated, natural spring and mineral water differences in the presence and number of bacteria during the two periods, winter and summer, are detectable.Methods: In our study, we analyzed and compared the following parameters, specified in the Rulebook: total bacteria and total aerobic bacteria (ml/22 and 37°C), total Coliform bacteria and Coliforms of fecalorigin (MPN/100ml), fecal streptococci as Streptococcus faecalis  (MPN/100ml), Proteus spp (MPN/100ml), and Pseudomonas aeruginosa (MPN/100 ml) Sulphoreducing Clostridia (cfu / ml). The paper is a retrospective study in which we processed data related to the period of 2005-2009 year. While working, we used the descriptive-analytical comparative statistical treatment.Results: The obtained results show statistically significant differences in the microbial composition of untreated water in the two observed periods,Conclusions: Findings were consequence of different weather conditions in these periods, which imply a number of other variable factors.

Legionella bacteria are microorganisms found in water and moist soil. They are especially favoured by moisture and heat, especially in different types of swimming pools where these bacteria reproduce and survive even for several months. Legionella spp. cause human diseases if they are introduced into the body through the respiratory tract. This most often happens by inhalation of aerosols, and less often by microaspiration of water contaminated with Legionella . The research aims to examine the presence of Legionella spp. bacteria in pool waters and the factors that influence their maintenance in these waters. Water samples were taken from 13 swimming pools that were registered for swimming and recreation in the Central Bosnian Canton in 2022. The presence of legionella was tested, and temperature, pH values (method BAS EN ISO 10523:2013), and residual chlorine concentrations were measured. The temperature was measured by immersing the probe with a calibrated thermometer until the stabilization of temperature values on the display was reached. The free residual chlorine was measured by the standard colourimetric technique – the N, N-diethyl-phenylenediamine method (HANNA Instruments 96701, Rhode Island, USA). Descriptive statistics and the Chi-square test will be used for data analysis. Statistical analysis of the obtained data will be performed using the basic functions of MS Excel and GraphPad Prism. Of the total number of analyzed samples (n = 13), the presence of legionella was confrmed in 4 samples (31 %). The average water temperature of the samples taken