Introduction: The aim of the study was to evaluate the occurrence of enterococci in inflammatory secretions from mastitic bovine udders and to assess their antimicrobial resistance. Material and Methods: A total of 2,000 mastitic milk samples from cows were tested in 2014–2017. The isolation of enterococci was performed by precultivation in buffered peptone water, selective multiplication in a broth with sodium azide and cristal violet, and cultivation on Slanetz and Bartley agar. The identification of enterococci was carried out using Api rapid ID 32 strep kits. The antimicrobial susceptibility was evaluated using the MIC technique. Results: Enterococci were isolated from 426 samples (21.3%). Enterococcus faecalis was the predominant species (360 strains), followed by E. faecium (35 isolates), and small numbers of others. The highest level of resistance was observed to lincomycin, tetracycline, quinupristin/dalfopristin (Synercid), erythromycin, kanamycin, streptomycin, chloramphenicol, and tylosin. Single strains were resistant to vancomycin and ciprofloxacin. All isolates were sensitive to daptomycin. E. faecalis presented a higher level of resistance in comparison to E. faecium, except to nitrofurantoin. Conclusion: The results showed frequent occurrence of enterococci in mastitic cow’s milk and confirmed the high rate of their antimicrobial resistance.

The paper concerns molecular study on pathogenicity markers of fourteen Y. enterocolitica O:9 isolated from pigs in which initially positive serological reactions for brucellosis were observed (n = 41), healthy pigs, which were brucellosis-negative (n = 258), and wild boars serologically negative for brucellosis (n = 209). PCR identification proved that all isolates were ail, ystA-and myfA-positive. The plasmid encoding yadA marker was detected in nine isolates that originated from pigs serologically positive or negative for brucellosis, and from one isolate of wild boar origin. Furthermore, none of the examined isolates was ystB-positive. Results of the investigations indicate that the Y. enterocolitica O:9 isolates from pigs or wild boars, regardless of whether they were serologically positive or negative for brucellosis, may also be potentially pathogenic for humans, due to the presence of chromosomal and plasmid encoded molecular markers.

No abstract

The aim of study was the preliminary evaluation of the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum ß-lactamases (ESBL) -producing Escherichia coli in 650 milk and inflammatory secretions from cows with clinical or subclinical mastitis. One millilitre of the sample was added to Mueller-Hinton broth supplemented with 6.5% NaCl, Tryptone Soya Broth with cefoxitin and aztreonam, and then to MRSA ID agar. Presumptive MRSA colonies were analysed for the presence of mecA gene. Parallel to MRSA identification, the samples were incubated in buffered peptone water, lauryl tryptose broth and McConkey agar supplemented with cefotaxim for ESBL-producing E. coli isolation. These bacteria were identified using API Rapid 32 E and the ability of ESBL production was initially established using disc test D68C and confirmed by MIC technique using Sensititre ESBL plates. The primers (blaCTX, blaTEM, blaSHV, and blaCMY-2-group) for the detection of some of the genes encoding ESBL production were used. The 45 strains of S. aureus with mecA gene and 41 strains of E. coli with blaTEM gene were detected.

Weiner M., Kubajka M. (2015), The importance of metagenomics research in human ecological niches and their role in the diagnosis of noninfectious diseases. Health Problems of Civilization, 2(9), p. 43-49.Summary: Human body is a complex system that is affected by a significant number of microscopic organisms called the microbiomes. The dynamic development of science has led to innovative discoveries in the field of microbiology. This in turn has extracted new field, metagenomics, thanks to which it became possible to perform detailed analysis of individual groups of bacteria and to determine their effects on preserving a good health. One of the biggest scientific projects that would investigate the influence of microbiomes on humans is HMP (Human Microbiome Project). As part of it the research is being conducted leading to characterize human microbiome at the level of nucleotide sequence of the entire genomic DNA. The microflora of the skin, oral cavity, respiratory tract, digestive tract (intestines), genitourinary system has an essential role in the homeostasis. In the last year the carried research proved that it is a vital part of the human organism in preserving a good health. Any changes in its composition may lead to systemic diseases. Pathological changes affect the outcome of the interaction within the microflora that includes species of commensal and pathogenic bacteria, as well as immunology and genetics of the host. Metagenomics research will contribute not only to the recognition of new, so far unidentified by the bacteriological methods microorganisms, but most of all they will serve as a basis to understand the relationships between the human organism and in-dwelling microorganisms. Thanks to the development of the metagenomics or the NGS (Next Generation Sequencing) it will be possible to discover new metabolic pathways and bidirectional links of bacteria with human metabolism. This will help in finding new therapeutic methods in the treatment of many noninfectious diseases so far considered as civilization diseases or genetically conditioned.