Antibiotic resistance in Staphylococcus aureus strains isolated from cows with mastitis in eastern Poland and analysis of susceptibility of resistant strains to alternative nonantibiotic agents: lysostaphin, nisin and polymyxin B.

The aim of this study was to analyze the resistance of Staphylococcus aureus isolates from bovine mastitis in the eastern part of Poland to a set of 20 antibiotics and three alternative agents: lysostaphin, nisin and polymyxin B. Eighty-six out of 123 examined isolates were susceptible to all 20 tested antibiotics (70%). The highest percentage of resistance was observed in the case of ß-lactam antibiotics: amoxicillin (n=22, 17.9%), ampicillin (n=28, 22.8%), penicillin (n=29, 23.6%) and streptomycin (n=13; 10.6%). Twenty-five of the penicillin-resistant strains were found to carry the blaZ gene coding for ß-lactamases. Two strains were found to be mecA positive and a few strains were classified as multidrug resistant (MDR), one of them was simultaneously resistant to six antibiotics. All strains, resistant to at least one antibiotic (n=37) and two control strains, were susceptible to lysostaphin with MIC values of 0.008-0.5 µg/ml (susceptibility breakpoint 32 µg/ml). Twenty-one (54%) isolates were susceptible to nisin. The MIC value of this agent for 17 (44%) strains was 51.2 µg/ml and was not much higher than the susceptibility breakpoint value (32 µg/ml). Polymyxin B was able to inhibit the growth of the strains only at a high concentration (32-128 µg/ml). The presented results confirmed the observed worldwide problem of spreading antibiotic resistance among staphylococci isolated from bovine mastitis; on the other hand, we have indicated a high level of bactericidal activity of nisin and especially lysostaphin.

[Resistance of Pseudomonas aeruginosa to antibiotics]. / Opornosc Pseudomonas aeruginosa na antybiotyki.

The main problem in the treatment of nosocomial infections is the increasing drug resistance of microorganisms that cause them, limiting the number of effective antibiotics. Pseudomonas aeruginosa bacilli are the cause of many serious hospital-acquired infections occurring primarily in patients within high-risk groups. The most vulnerable are those with weakened immune systems, as well as those with extensive surgical wounds and burn wounds. Infections are usually of the nature of secondary infections, caused by multidrug strains. Due to the high antimicrobial activity, beta-lactams, aminoglycosides and quinolones are drugs commonly used in hospitals, both in prevention and treatment of infections with P. aeruginosa. However, their irrational use is associated with selection and spread of strains resistant to these antibiotics. Resistance of P. aeruginosa to antibiotics is the result of a number of independent co-occurring mechanisms. These are: reducing the membrane permeability, the efflux system, and production of enzymes inactivating and degrading antibiotics. The paper devotes special attention to the determination of resistance mechanisms responsible for this phenomenon.

Biofilm production and presence of ica and bap genes in Staphylococcus aureus strains isolated from cows with mastitis in the eastern Poland.

The aim of the study was phenotypic and genotypic analysis of 132 S. aureus strains isolated from mastitis in eastern Poland in respect to their biofilm formation ability. The analysis of the size polymorphism of fragment X in the gene encoding protein A (spa) revealed high genetic differentiation of the analyzed group of isolates. The ability of biofilm formation by the isolates was tested using two phenotypic methods. The Congo Red plate assay was found to be irreproducible and very subjective. More objective results were obtained using the spectrophotometric, microtiter plate assay. Most of the isolates, namely 76/132 (57.6 %) were classified as biofilm producers depending on the value of absorbance in the microtiter plate test. All of the isolates tested were found to possess both icaA and icaD genes, while the bap gene was absent in all strains.

Survey on composition and bioconcentration potential of 12 metallic elements in King Bolete (Boletus edulis) mushroom that emerged at 11 spatially distant sites.

This paper provides data on baseline concentrations, interrelationships and bioconcentration potential of 12 metallic elements by King Bolete collected from 11 spatially distant sites across Poland. There are significant differences in concentrations of metals (Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Sr, Zn) and their bioconcentration potential in King Bolete Boletus edulis at 11 spatially distant sites surveyed across Poland. These have resulted from significant geographical differences in trace metal concentrations in a layer (0-10 cm) of organic and mineral soil underneath to fruiting bodies and possible local bioavailabilities of macro- (Ca, K, Mg, Na) and trace metals (Al, Ba, Cd, Cu, Fe, Mn, Sr, Zn) to King Bolete. The use of highly appreciated wild-grown edible King Bolete mushroom has established a baseline measure of regional minerals status, heavy metals pollution and assessment of intake rates for wild mushroom dish fanciers against which future changes can be compared. Data on Cd, Cu and Zn from this study and from literature search can be useful to set the maximum limit of these metals in King Bolete collected from uncontaminated (background) areas. In this report also reviewed are data on Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Sr and Zn accumulation in King Bolete.

Profile and bioconcentration of minerals by King Bolete (Boletus edulis) from the Plocka Dale in Poland.

This study aimed to provide basic data on the composition of metallic elements, including toxicologically important Cd and Hg, in popular and prized wild King Bolete mushrooms. We investigated the importance of soil substratum as a source of these metals. ICP-OES and CV-AAS were applied to determine the profile of Al, Ba, Ca, Cd, Cu, Fe, Hg, K, Mg, Mn, Na, Sr and Zn in caps and stipes of King Bolete mushroom and in the surface layer of soil (0-10 cm) from the Plocka Dale area of Poland. Hg, Cu, Cd, Zn, Mg and K exhibited bioconcentration factors (BCF) > 1. Specifically, Hg, Cu and Cd (mean BCFs for caps were 110, 19 and 16, respectively) were efficiently bioconcentrated by King Bolete, while other elements were bioexcluded (BCF < 1). Cadmium was present in the caps at mean levels of 5.5 ± 2.4 mg kg(-1) dry weight (dw) and mercury at levels of 4.9 ± 1.4 mg kg(-1) dw, both occurring at elevated concentrations in those King Bolete mushrooms surveyed.

Mercury and its bioconcentration factors in King Bolete (Boletus edulis) Bull. Fr.

The total mercury content for a representative number of the carpophores of King Bolete from 13 sites across Poland averaged from 1.1 +/- 1.4 to 7.6 +/- 3.1 microg/g dry matter in the caps (total variation between 0.02 and 14 microg/g dm), and from 0.82 +/- 0.71 to 3.8 +/- 1.8 microg/g dm in stalks (total variation between 0.03 and 6.7 microg/g dm). A top soil layer (0-10 cm) collected from the mushroom sampling sites showed mean mercury content at range from 0.02 +/- 0.01 to 0.05 +/- 0.02 microg/g dm (total variation between 0.01 and 0.08 microg/g dm). King Bolete is effective mercury accumulator in the carpophores and bioconcentration factor (BCF) of this element in the caps ranged from 41 +/- 6 to 130 +/- 39 (total variation between 13 and 170) and in the stalks were from 27 +/- 18 to 72 +/- 22 (total variation between 4.0 and 90). Based on a relatively large set of data on the total mercury concentrations obtained in this survey, and dataset available for King Bolete from various sites in Europe, it seems reasonable to state that the upper food hygienic limit for the total mercury content in this species collected from unpolluted (background) sites should not exceed 20 microg/g dm in a single cap or a carpophore, while on an average, per site or consignment, should not exceed 10 mug/g dm in the caps or the carpophores.

[Arsenic, cadmium, lead and mercury in king bolete Boletus edulis and tolerance limits]. / Arsen, kadm, olów i rtec w borowiku szlachetnym Boletus edulis a tolerancje.

In the article are reviewed and discussed available data on arsenic, cadmium, lead and mercury content of the fruiting bodies of king bolete. The values of cadmuim concentration of the fruiting bodies of king bolete collected from the areas unpoluted with metals and metaloids in Poland and other European countries usually are greater than an actual tolerance limits set by E.U. law for 0.2 mg/kg wet weight in cultivated mushrooms. Analogically, as is for cadmium also content of lead to be sometimes greater than tolerance limit of 0.3 mg/kg w.w. set in EU for cultivated mushrooms. The fruiting bodies of king bolete usually are also relatively rich in mercury at concentration much greater when compared to tolerance limit set earlier in Poland (in E.U. there is no tolerance limit for mercury in mushrooms). In the case of cadmium it can bee agreed, that this element content of pooled samples of the fruiting bodies of king bollete collected from unpolluted regions usually will not exceed a value of 20 mg/kg d.m., while at polluted areas will exceed a value of 20 mg/kg d.m. In the case of mercury it can bee agreed, that this element content of pooled samples of the fruiting bodies of king bollete collected from unpolluted regions usually will not exceed a value of 5 mg/kg d.m., while at polluted areas will exceed a value of 5 mg/kg d.m. In the case of lead it can be agreed, that this element content of some percent of pooled samples of the fruiting bodies of king bolete collected from unpoluted regions will sometimes exceed an actual the EU tolerance limit of 0.3 mg/kg w.w. as set only or cultivated mushrooms. In the case of arsenic it can be agreed, that total arsenic contant of some percent of pooled samples of the fruiting bodies of king bolete collected from unpoluted regions will exceed value of 0.50 mg/kg d.m.