The objectives of this study are to determine the prevalence of Staphylococcus aureus in nasal and throat swab samples collected from healthy individuals within a population of workers and students, analyze its frequency in relation to the gender distribution of partici- pants, and assess the antibiotic susceptibility profile. S. aureus was isolated exclusively from nasal swab samples (111/1403). The findings indicate that nasal carriage is significantly more prevalent in male participants than in females and is independent of age. No statistically significant differences in S. aureus prevalence were observed between the worker and student populations. Resistance was detected for: penicillin, ampicillin, amoxicillin/clavulanate, oxa- cillin, cephalexin, gentamicin, erythromycin, chloramphenicol, trimethoprim-sulfamethoxaz- ole and ciprofloxacin. Further research involving a larger sample size and an extended study period is required to elucidate the influence of geographic and sociodemographic factors on S. aureus carriage, as well as the potential impact of gender on the prevalence of resistant strains.

Pseudomonas aeruginosa is an opportunistic pathogen that frequently causes infections in immunocompromised patients and is involved in outbreaks of hospital-acquired infections with a high mortality rate. Aminoglycosides are a large category of antibiotics that bind specifically to 16S rRNA in 30S ribosomal subunits and disturb protein translation. This antibiotic class plays a significant bactericidal role against a wide range of Gram-negative bacteria such as P. aeruginosa. Among different aminoglycoside resistance mechanisms, inactivation of drugs by plasmid-encoded aminoglycoside-modifying enzymes (AMEs) is a common determinant of aminoglycoside resistance in  P. aeruginosa. These plasmids are spread worldwide, and they are transferred to a wide range of different species. This study aims to detect resistance mechanisms and  identify the most prevalent aminoglycoside resistance genes in P. aeruginosa clinical isolates, collected from the University Clinical Centre Tuzla. This study included a total of 230 clinical P. aeruginosa isolates. Antimicrobial susceptibility tests were performed using the disk diffusion method and the Vitek2 system. Isolates displaying increased MIC values for aminoglycoside antibiotics were included in the multiplex PCR reaction, for the detection of aminoglycoside-modifying enzyme genes. The most prevalent genotype among isolates was aac (6')-I. All aac (6')-I genotyped isolates also displayed a high rate of resistance to other classes of antibiotics, and they were characterized as multidrug-resistant (MDR) or extensively drug-resistant (XDR). Results indicate that the aminoglycoside-resistance genes are highly prevalent and could easily spread among P. aeruginosa strains.

The aim of the study is the isolation and identification of fungi using passive air sedimentation. This study analyzed 540 mycological samples from three primary schools in Zenica, collected in September, December, February, and May. Each season, 135 samples were taken from five rooms (two classrooms, a gym, a locker room, and a library) in each school. Samples were collected three times daily at three different heights with 15-minute exposure times. Samples were refrigerated and transported in sterile bags, incubated for 24 hours, and inoculated on specific agars with and without additives. Plates were incubated at 37°C and 25°C for up to 7 days, followed by examinations. Petri dishes were used for passive air sampling, and colonies were counted after incubation. The average number of microorganisms (CFU/m³) was calculated using Omeliansky’s method. Statistical methods included the Chi-squared test and p-value. Colony appearance was assessed visually and microscopically using a light microscope. Growth rate, size, structure, and color changes were monitored. In September, the highest mold concentrations were at H. Kikić Primary School (796 CFU/m³, not significant), M. Dizdar Primary School (1260 CFU/m³, not significant), and A. Šantić Primary School (3980 CFU/m³, significant). Penicillium spp. and Alternaria spp. were most prevalent, with Alternaria spp. significant at H. Kikić Primary School. In December, the highest mold/yeast concentrations were at H. Kikić Primary School (4578 CFU/m³, not significant), M. Dizdar Primary School (1924 CFU/m³, significant), and A. Šantić Primary School (2587 CFU/m³, not significant). Penicillium spp. was most prevalent. In February, the highest mold concentrations were at H. Kikić Primary School (4578 CFU/m³, not significant), M. Dizdar Primary School (2786 CFU/m³, not significant), and A. Šantić Primary School (5838 CFU/m³, significant). Aspergillus spp. and Penicillium spp. were equally prevalent. In May, the highest mold/yeast concentrations were at H. Kikić Primary School (6568 CFU/m³, significant), M. Dizdar Primary School (3516 CFU/m³, significant), and A. Šantić Primary School (7431 CFU/m³, significant). Aspergillus spp. was most prevalent. These findings highlight the importance of regular monitoring and implementing appropriate ventilation measures to manage air quality and health concerns in schools.

The aim of this study was to determine the frequencies of alleles and genotypes of the single nucleotide polymorphism of the FTO gene (rs17817449) and the intensity of physical activity in relation to the BMI of subjects in the student population. Genotyping was performed using the PCR-RFLP method. 94 subjects stated that they were not physically active, 57 subjects were moderately physically active and 52 were intensely physically active. In the total sample, the risk allele G of the investigated polymorphism rs17817449 of the FTO gene had a lower frequency (41.8%) compared to the normal allele T (58.13%). Although a higher frequency of the risk allele G was found in the group of overweight subjects compared to the group with BMI < 25, the difference was not statistically significant (p > 0.05).

Nowadays, bottled water has become part of the lifestyle, replacing tap water, and water from freestanding dispensers is increasingly being used. The main goal of this research was to determine the health suitability of bottled water in freestanding dispensers. The research included the microbiological analysis of a total of 100 samples of bottled water from freestanding dispensers. The samples were mostly taken in the wider area of the city of Doboj (doctor's offices, shops, public buildings), and one dispenser in the city of Tuzla. Water samples were taken twice, in the period from April to June 2022. Water samples from 6 different manufacturers (Vivia, Kristal, Nevra, Gora, Aqua doria, Aqua team) were analyzed. 9% of water samples (9/100) were microbiologically correct. Microbiologically defective samples contained a higher total number of bacteria at 22°C and 37°C, as well as a higher number of coliform bacteria than the maximum allowed values. No significant differences in microbiological quality were found between older and/or recently installed water dispensers, as well as in terms of environmental conditions, while visible differences were observed between dispensers that were regularly hygienically maintained.KEYWORDS:dispensers; bottled water; coliform bacteria; biofilms; total bacteria count

Insertion/deletion polymorphism of the angiotensin converting enzyme (ACE) gene is a key component of the Renin-Angiotensin-Aldosterone System (RAAS). It has been proposed as an independent factor for hypertension and other cardiovascular diseases. Consequently, it has been extensively studied in various populations. The aim of this study is to investigate I/D polymorphism of ACE gene and its connection to hypertension in population of Tuzla Canton (Bosnia & Herzegovina). The study included 60 hypertensive subjects and 60 healthy control subjects with no risk factors for hypertension. I/D polymorphism was genotyped by polymerase chain reaction followed by gel electrophoresis and data obtained were statistically analysed using Chi square test. Odd’s ratios were calculated with a 95% confidence interval. P-value < 0.05 was considered significant. Odd’s ratios were calculated with a 95% confidence interval. P-value <0.05 was considered significant. Higher frequency of genotype D/D and allele D was determined in subjects with hypertension compared to control subjects but there is no statistical significance (p>0.05). However, statistically significant association was found in compared groups of subjects with genotypes DD + ID, in regards to genotype I/I (p<0.05). The results indicate the conclusion that ACE I/D polymorphism cannot be considered the main risk factor for development of hypertension, but its influence should be investigated together with other genetic and acquired risk factors that are associated with hypertension. This research contributes to the on-going exploration of molecular-genetic associations with hypertension.

Molecular-genetic diagnostics of polygenic diseases is a new and interesting area in laboratory diagnostics, especially in the area of cardiovascular diseases, as one of the leading causes of mortality in the world population. Aims: The aim of the paper was to analyse variants of the endothelial nitric oxide synthase gene (NOS3) (Glu298Asp/G894T) in the human population of Tuzla Canton in relation to cardiovascular diseases. Study Design: The study included 112 respondents of both sexes over 18 years old. The experimental group for the analysis of the polymorphism (Glu298Asp) of the endothelial nitric oxide synthase gene included 56 respondents of both sexes with cardiovascular disease (hypertension), while the control group comprised 56 healthy respondents of both sexes without a prior history of cardiovascular disease (sample/control). Place and Duration of Study: Blood sampling was performed at Medical Center "Plava Poliklinika", “Plava Medical Group”, Department of Biochemistry, Microbiology and Genetics, Tuzla. DNA isolation and molecular-genetic analysis of the samples were performed in Laboratory for scientific research at the Department of Biology, Faculty of Natural Sciences and Mathematics in Tuzla. Methodology: The genotyping of eNOS Glu298Asp polymorphism for all respondents was determined by an optimized method based on PCR-RFLP reaction. Results: In the total sample of respondents, the highest genotype frequencies of the eNOS gene were recorded for the GG genotype (53.5%) and the GT genotype (35.7%). The lowest frequency was recorded for the TT genotype, which was 10.8%. Conclusion: The results obtained in the study provide good guidelines for further study of a molecular-genetic association between a high number of gene candidates and cardiovascular diseases, which will contribute to the incorporation of these results into the existing regional and European genetic database.

Aims: The aims of this study was to investigate the susceptibility of extended-spectrum beta-lactamase (ESBL) producing Klebsiella pneumoniae clinical isolates to antibiotics and essential oils - Origanum compactum, Origanum majorana and Thymus serpyllum. Study Design: Study included 30 isolates of Klebsiella pneumoniae obtained from clinical material provided from the University Clinical Center Tuzla. Place and Duration of Study: Department of Biology, Faculty of Science, University of Tuzla, BiH, between September 2019 to September 2020. Methodology: Antibiotic susceptibility testing was performed by the Kirby-Bauer disk diffusion method. The following commercially available antibiotic discs were used: amoxicillin (30µg), cefalexin (30 µg), gentamicin (10 µg), amikacin (30 µg), imipenem (10 µg), piperacillin (75µg), ampicilin (10 µg), meropenem (10 µg), ciprofloksacin (10 µg), ceftazidim (30 µg), cefotaksim (30 µg), ceftriaxone (30 µg), cefepime (30 µg) and aztreonam (30 µg). The antibacterial effect of the essential oils was tested for ESBL K. pneumoniae isolates using the diffusion method according to Clinical laboratory standards institute (CLSI) guidelines. Results: O. compactum and O. majorana essential oils showed the same antimicrobial activity with 80.0% effect on ESBL K. pneumoniae isolates, Thymus serpyllum EO showed antimicrobial activity of 60.0%. The lowest MIC value had the O. compactum essential oil (MIC 6 mg/ml-10.5 mg/ml), followed by the T. serpyllum (MIC 17.2 mg/ml-43 mg/ml), while the O. majorana essential oil showed MIC values in range from 11 mg/ml to 39 mg/ml. Conclusion: The results of the study showed the exceptional sensitivity of ESBL K. pneumoniae clinical isolates to the essential oils from Origanum and Thymus genera, which highly suggests their potential application in the struggle against these pathogens in the future.