This study investigated 960 Slovak and Czech spotted cattle from four different conventional (non-organic) dairy herds located in Eastern Slovakia and Czechia during early lactation (14–100 days after calving). Dairy cows were examined clinically; milk from fore-stripping of each udder quarter was subjected to sensory examination and assessed by the California mastitis test (CMT), and laboratory analyses of bacterial pathogens in milk, including virulence factors, were conducted. Positive CMT scores (1–3) for one or more quarters were detected in 271 (28.2%) of the examined animals. Out of 230 infected milk samples, representing 24.0% of all dairy cows, staphylococci (59.1% of positive findings) were the most commonly isolated organisms, followed by E. coli (11.3%), streptococci Str. uberis (9.1%) and Str. agalactiae (3.4%), and enterococci (6.1%). From 136 isolates of S. aureus (38 isolates) and non-aureus staphylococci (NAS; 98 isolates), virulence factors and their resistance to 14 antimicrobials were detected using the disk diffusion method, with PCR detection of the methicillin resistance gene, mecA. An increased incidence of clinical and chronic forms of mastitis has been reported in mastitic cows in which staphylococci, especially S. aureus and NAS (S. chromogenes, S. warneri, and S. xylosus), have been detected and compared to other isolated udder pathogens. From those species, S. aureus and isolates of NAS mentioned above showed multiple virulence factors that are more likely to hydrolyze DNA, hemolysis, produce gelatinase and biofilm, and have multi-drug resistance as compared to other less virulent staphylococci. Generally, the isolated staphylococci showed 77.2% resistance to one or more antimicrobials, in particular to aminoglycosides, β-lactams, macrolides, or cephalosporins. Isolates that showed the ability to form a biofilm were more resistant to more than one antimicrobial than isolates without biofilm production. Multi-drug resistance to three or more antimicrobial classes was recorded in 16 isolates (11.7%), and the presence of the mecA gene was also confirmed in two isolates of S. aureus and two species of NAS.

This study aimed to calculate the proportion of antibiotic resistance profiles of Enterococcus faecium, E. faecalis, and E. durans isolated from traditional sheep and goat cheeses obtained from a selected border area of Slovakia with Hungary (region Slanské vrchy). A total of 110 Enterococcus sp. were isolated from cheese samples, of which 52 strains (E. faecium (12), E. faecalis (28), E. durans (12)) were represented. After isolation and identification by polymerase chain reaction and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry, the enterococci (E. faecium, E. faecalis, and E. durans) were submitted to susceptibility tests against nine antimicrobial agents. In general, strains of E. faecalis were more resistant than E. durans and E. faecium. A high percentage of resistance was noted in E. faecalis to rifampicin (100%), vancomycin (85.7%), teicoplanin (71.4%), erythromycin (71.4%), minocycline (57.1%), nitrofurantoin (57.1%), ciprofloxacin (14.3%), and levofloxacin (14.3%). E. durans showed resistance to rifampicin (100%), teicoplanin (100%), vancomycin (66.7%), erythromycin (66.7%), nitrofurantoin (66.7%), and minocycline (33.3%), and E. faecium showed resistance to vancomycin, teicoplanin, and erythromycin (100%). Multidrug-resistant strains were confirmed in 80% of the 52 strains in this study. Continuous identification of Enterococcus sp. and monitoring of their incidence and emerging antibiotic resistance is important in order to prevent a potential risk to public health caused by the contamination of milk and other dairy products, such as cheeses, made on farm level.

This study was conducted to evaluate the incidence of mastitis in 153 dairy cows and to evaluate the kinetics of adhesion of isolates obtained from surfaces and milk in comparison with the reference strain (RS), CCM 4223. The surfaces of the floor, teat cup, and cow restraints were aseptically swabbed in three replicates (n = 27). Of the total number of infected cows (n = 43), 11 samples were found to be positive for Staphylococcus aureus, 12 samples tested positive for non-aureus staphylococci, 6 samples tested positive for Streptococcus spp., and 11 samples tested positive for other bacteria (Escherichia coli, Pseudomonas spp.) or a mixed infection. The most represented pathogen in milk (11/43) and on surfaces (14/27) was S. aureus. The kinetics of adhesion of the reference strain and isolates of S. aureus on stainless steel surfaces were determined after 3, 6, 9, 12, 24, and 48 h, and 3, 6, 9, 12, and 15 days of incubation. All strains reached counts higher than 5 Log₁₀ CFU/cm² needed for biofilm formation, except RS (4.40 Log₁₀ CFU/cm²). The isolates of S. aureus revealed a higher capability to form biofilm in comparison with RS during the first 3 h (p < 0.001). Thus, there is a significant difference between the occurrence of S. aureus on monitored surfaces—floor, teat cup, and cow restraints—and the frequency with which mastitis is caused by S. aureus (p < 0.05). This finding raises the possibility that if various surfaces are contaminated by S. aureus, it can result in the formation of biofilm, which is a significant virulence factor.

The aim of this study was to compare three on-farm commercial methods for the indirect detection of subclinical mastitis in dairy cows: the California mastitis test (CMT), the Porta side somatic cell count milk test (Porta SCC), and the DeLaval cell counter (DCC), with the Fossomatic cell count (FSCC), and to evaluate the relationship between the determined somatic cell count SCC and the occurrence of intramammary pathogens in the milk of dairy cows. A total of 284 sensory unchanged mixed milk samples, collected during the milking on a dairy farm, were analyzed in this study for somatic cell counts by the mentioned on-farm tests. Quarter milk samples (n = 583) from all the selected cows were cultured. The agreement, sensitivity, and specificity of the three indirect commercial diagnostic tests (the CMT, the Porta SCC, and the DeLaval cell counter) were calculated, and the FSCC was used as the gold standard. The results were analyzed statistically using the Pearson correlation test and the paired t-test. The CMT matched with the FSCC in 83.1% of the samples, with the Porta SCC in 80.6%, and with the DCC in 80.3% of the samples. The sensitivity and specificity reached 81.0% and 92.9% for the CMT, 79.4% and 90.7% for the Porta SCC, and 75.8% and 97.5% for the DCC, respectively. The correlation between the FSCC and the Porta SCC was 0.86 (p < 0.0001), and between the FSCC and the DCC, it was 0.92 (p < 0.0001). The differences between them were insignificant. Bacteria were detected in 130 (22.3%) quarter milk samples. The most prevalent bacteria were Enterococcus spp. (36.2%), followed by E. coli (20%), coagulase-negative staphylococci (13.1%), A. viridans (9.2%), Streptococcus spp. (9.2%), Proteus spp. (6.2%), and S. intermedius (3.9%). Contagious isolates (S. aureus) were detected in 3 quarter milk samples (2.3%). The agreement between the individual tests and the microbiological culture was as follows: 69.2% for the CMT; 73.7% for the Porta SCC; 71.6% for the DCC; and 76.5% for the FSCC. Higher SCCs were detected in the milk samples contaminated with bacteria than in the healthy milk (p < 0.001). No significance was found between the presence of individual species of intramammary pathogens and the different levels of SCCs. Based on the results, bacteria are the predominant cause of subclinical mastitis. The increased SCC of some milk samples with no presence of bacteria meant that the increase could have been caused by numerous other agents (viruses, fungi, or algae) or factors for mastitis in the dairy industry.

The aim of study was to investigate the effect of amendment of cow manure with natural zeolite-clinoptilolite and hydrated lime on decomposition processes over the period of 90 days. Two static piles of amended substrates were constructed consisting of cow manure with an addition of bulking material (2.5% by weight): (1) manure mixed with zeolite (S1); manure mixed with zeolite and lime (S2). Third amendment-free pile served as a control (C). During the experiment, pH level, temperature (T), dry matter (DM), ash, organic matter (OM), C/N ratio, ammonia nitrogen (N-NH₄⁺) and total nitrogen (N_t) were determined. We also determined the counts of total coliform and faecal coliform bacteria and faecal streptococci as indicators of the hygiene level of compost. A significant increase (p < 0.001) in temperature to 53 °C was observed in S2 compared to C. In S2 we observed a significantly reduced release of N-NH₄⁺ from the composting substrate compared to C (p < 0.05). The significant differences were in N_t content in C and S2 (p < 0.001) and between S1 and S2 (p < 0.05). The concentration of N_t increased and caused decrease in the C/N ratio. The content of N_t in the substrates with zeolite increased by 44% in S1 and 45% in S2 compared to C. The differences in counts of coliform and faecal coliform bacteria between C and S2 were significant (p < 0.001). This experiment showed that amendment with zeolite and lime decreased nitrogen losses during composting and indicated sorption effects of zeolite.

The environment is severything that creates natural conditions for the existence of organisms, including humans, and is a prerequisite for its further development. Proper environmental hygiene can prevent the outbreak and spread of infectious diseases. The function of disinfectants is to kill and prevent the growth of microorganisms. Disinfectants are potentially noxious substances which are used in intensive animal production and disease control programmes. In fulfilling this role, disinfectants may also have an adverse impact on the environment. These products may harm beneficial microorganisms, plant and animal life, and even humans, when used without due caution. Proper selection of disinfectant which is based on the knowledge of the resistance of microorganisms to the effect of the disinfectant and the efficacy of the disinfectants as well as the potential negative impact on the environment minimizes the risk of microbiological contamination and improves quality of the environment.