Proteus mirabilis is the third most common etiological factor of urinary tract infection. It produces urease, which contributes to the formation of a crystalline biofilm, considered to be one of the most important virulence factors of P. mirabilis strains, along with their ability to swarm on a solid surface. The aim of this study was to analyze the pathogenic properties of two selected groups of clinical P. mirabilis isolates, antimicrobial susceptible and multidrug resistant (MDR), collected from hospitals in different regions in Poland. The strains were examined based on virulence gene profiles, urease and hemolysin production, biofilm formation, and swarming properties. Additionally, the strains were characterized based on the Dienes test and antibiotic susceptibility patterns. It turned out that the MDR strains exhibited kinship more often than the susceptible ones. The strains which were able to form a stronger biofilm had broader antimicrobial resistance profiles. It was also found that the strongest swarming motility correlated with susceptibility to most antibiotics. The correlations described in this work encourage further investigation of the mechanisms of pathogenicity of P. mirabilis.

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Proteus mirabilis is the third most common etiological factor of the urinary tract infection (UTI). It produces urease, which contributes to the formation of crystalline biofilm, considered to be one of the most important virulence factors of P. mirabilis strains, along with their ability to swarm on a solid surface. The aim of this study was to analyze the pathogenic properties of two selected groups of clinical P. mirabilis isolates, antimicrobial-susceptible and multidrug-resistant (MDR), collected from hospitals in different regions in Poland. The strains were examined based on virulence gene profiles, urease and hemolysin production, biofilm formation, and swarming properties. Additionally, the strains were differentiated based on the Dienes test and antibiotic susceptibility patterns. It turned out that the MDR strains exhibited kinship more often than susceptible ones. The strains which were able to form stronger biofilm had broader antimicrobial resistance profiles. It was also found that the strongest swarming motility correlated with susceptibility to most antibiotics. The correlations described in this work encourage further investigation of the mechanisms of pathogenicity of P. mirabilis.Author summaryProteus mirabilis is widely widespread in environment but also it is responsible for most Proteus infections, especially in human urinary tracts. They cause complicated, persistent infections especially due to the ability to form urinary stones. The clinical importance of P. mirabilis have been described in the literature many times. However, the role of pathogenic features with correlation to drug resistance require further investigation. In this research we analyzed thee virulence factors in relation to drug resistance of clinical P. mirabilis strains isolated from urine. The virulence genes, ureolytic and hemolytic activity, biofilm formation, swarming growth and strains kindship were analyzed. The most important observation was that the strains exhibited a stronger territorialism were kindred to a lower number of other strains, formed weaker biofilm and exhibited a lower resistance to antibiotics. Furthermore, we proved that the strains which were more likely to mutual growth, they were also less similar in the drug resistance profile but exhibited a higher resistance to antibiotics, which can be beneficial for different bacteria living together. We believe that P. mirabilis with strong territorialism can represent a wild group of strains with poor experience of antibiotic pressure. The environmental influence (toxins, antibiotics, bacterial neighbors) stimulates the development of a less dispersed community with stronger biofilm, exchange of genes and increase of resistance to antibiotics.

Introduction: Water is a convenient environment for the spread of pathogenic bacteria. Their presence may result from contact with water through soil, air, and animal and human activity. The identification of microorganisms allows us to determine the biological properties, the possible epidemiological risk, and the sanitary condition of the surface water. Aim of the research: To analyse the presence of microbiological indicators in selected water samples collected in autumn, winter, and spring. Material and methods: The research sites included three rivers and two water reservoirs located in Świętokrzyskie voivodeship. The water samples were tested based on the presence of coliform, mesophilic, and psychrophilic bacteria. Results: The presence of E. coli was confirmed in all water reservoirs, but values above the standard limit were confirmed in just three cases (Wisła, Bernatka, and Emerald Lake). The results show that the changing microbiological parameters of the analysed water samples can result from different factors. The large number of bacteria in water can come from other local streams and groundwater, human and animal activity, and especially from influx of domestic wastewater. The sanitary state of surface water in Świętokrzyskie is consistent with data from other Polish voivodeships published in the literature. Conclusions: Microbiological pollution of surface water in Poland is a constant and underestimated problem. It can be a serious epidemiological threat, especially in mild winters and warmer summers. Streszczenie Wprowadzenie: Woda jest dogodnym środowiskiem do rozprzestrzeniania się bakterii chorobotwórczych. Ich obecność może wynikać z kontaktu wody z glebą, powietrzem, zwierzętami i z działalności człowieka. Identyfikacja mikroorganizmów pozwala określić właściwości biologiczne, ryzyko epidemiologiczne i stan sanitarny wód powierzchniowych. Cel pracy: Analiza obecności wybranych wskaźników mikrobiologicznych (ogólna liczba bakterii mezofilnych i psychrofilnych, obecność Escherichia coli, miano coli) w próbkach wody pobranych jesienią, zimą i wiosną z pięciu różnych zbiorników. Materiał i metody: Badaniami objęto 3 rzeki i 2 zbiorniki wodne położone w województwie świętokrzyskim. Próbki wody testowano na obecność bakterii coli oraz ogólnej liczby bakterii mezofilnych i psychrofilnych. Wyniki: Obecność E. coli została potwierdzona we wszystkich zbiornikach wodnych, ale normy były przekroczone w trzech przypadkach (Wisła, Bernatka i Szmaragdowe Jezioro). Wyniki pokazują, że zmiana parametrów mikrobiologicznych analizowanych wód może wynikać z różnych przyczyn. Duża liczba bakterii w wodach może pochodzić z innych, lokalnych strumieni i wód gruntowych, aktywności zwierząt i ludzi, zwłaszcza z napływu domowych ścieków. Stan sanitarny wód powierzchniowych w województwie świętokrzyskim jest zgodny z danymi z innych polskich województw opublikowanymi w piśmiennictwie. Wnioski: Zanieczyszczenie mikrobiologiczne wód powierzchniowych w Polsce jest problemem stałym i bagatelizowanym. Może stanowić poważne...

The clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins are components of the adaptive immunity system, protecting against foreign DNA, which are present in many bacteria species. Recent years have brought extensive research on this system however, not all of its biological properties have been discovered so far. It was recently discovered that CRISPR-Cas can regulate the formation of biofilm and is closely associated with the DNA repair system in bacterial cells. It is also likely that some of the spacer sequences are complementary to short sequences in the bacterial genome, which may have an influence on regulation of bacterial genes, e.g. virulence factors. Besides, phages can synthesize anti-CRISPR genes, which could be of use in the future for the purpose of development of an alternative therapy against multi-drug resistant bacterial strains. Here we present an elementary characteristic of CRISPR-Cas system, including the structure and the brief mechanism of action, systematic classification and its importance for medicine and biotechnology issues. We would like to stress the huge potential of CRISPR-Cas by discussing the selected but varied aspects. 1. Introduction. 2. Structure, operation and differences. 3. Bacterial typing. 4. Correlation with bacterial pathogenicity. 5. Potential tool for medicine. 5.1. CRISPR-tool for genome editing. 5.2. Instances of CRISPR-tool strategies in medicine. 6. Phage response. 7. Conclusions