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Pathogens carried by ticks pose a threat to both human and animal health across the world. Typically associated with rural landscapes, ticks appear to adapt well to life in urban recreational areas. Although Dermacentor reticulatus is commonly found across Europe, data on the prevalence of pathogens in this tick species, in an urban environment, are very limited. PCR was used to examine 368 D. reticulatus individuals collected in the Zwierzyniecki Forest Nature Reserve in Białystok, Poland. In total, 10.3% of ticks were infected, with Babesia spp. (9.2%), Anaplasma phagocytophilum (0.8%) and Borrelia burgdorferi sensu lato (0.3%). Rickettsia spp., Bartonella spp., and Coxiella burnetii were not detected. Sequence analysis for Babesia-positive samples identified 79.4% of them as Babesia canis, 8.8% as Babesia microti, 5.9% as Babesia spp., 2.9% as Babesia venatorum, and 2.9% as Babesia vogeli. Results obtained in this study indicate that D. reticulatus ticks found within the urban premises of the study area are infected with at least three pathogens and therefore are an important factor in public health risk for tick-borne diseases.

Objectives The growing incidence of multidrug-resistant (MDR) bacteria is an emerging challenge in modern medicine. The utility of carbapenems, which are considered ‘last-line' agents, is being diminished by the growing incidence of various resistance mechanisms in Gram-negative bacteria. A molecular investigation was performed of an MDR carbapenem-resistant Citrobacter freundii of sequence type 8 (ST8) isolated from a hematology patient with acute myeloid leukemia. Methods Multilocus sequence typing and analysis of the nucleotide sequence of the class I integron were performed using PCR and Sanger sequencing. Transformation of the resistance plasmid isolated following the alkaline lysis method was performed using chemically competent E. coli TOP10. Results Molecular analysis of the carbapenem-resistant C. freundii revealed the presence of the VIM-4 isoenzyme located on the ∼55-kb transferable resistance plasmid. Interestingly, the bla VIM-4 gene was inserted into an unusual gene cassette containing a 169-bp direct repeat of the 3′ segment of the bla VIM-4 gene. Conclusions All unusual gene cassettes containing VIM-DR (direct repeat) described thus far have been harbored by non-fermenters, i.e., Acinetobacter and Pseudomonas, underscoring the importance of resistance determinant mobility, which may go even beyond genus, family, and order boundaries. Great efforts need to be taken to explore pathways of resistance to ‘last-resort' antimicrobials, especially among clinically relevant pathogens.

Purpose: Enterococcus faecium strains have been reported worldwide as etiologic factors of many nosocomial infections, which are difficult to manage because of the constantly increasing resistance of these microorganisms to antibiotics and the ability to form biofilm. The aim of this study was to analyze the ability to produce a biofilm in E. faecium strains, depending on the patient’s clinical material. Materials and methods: Sixty-six E. faecium strains were investigated. Identification and susceptibility testing were conducted by the VITEK2 system. The ability to form biofilm was assessed by phenotypic methods. The presence of selected virulence genes was established by PCR followed by gel electrophoresis and sequencing. Results: Among the tested E. faecium isolates, 72.7% were biofilm-positive (BIO+) and 27.3% biofilm-negative (BIO-). Strains were collected mostly from rectal swabs (30.4%) and blood (18.3%). BIO+ strains from infections constituted 31.8% (52.4% isolated from blood) and from colonization 40.9% (48.2% from rectal swabs). 91.7% of the Blood Group strains and 68.5% of the Other Group strains produced biofilm. Strains from the Colonization Group produced biofilm in a proportion similar to the Infection Group (about 75%). There were no statistically significant differences in virulence and resistance, except for vancomycin (more resistant BIO+ Other than the BIO+ Blood Group, and more resistant BIO+ Colonization than BIO+ Infection Group) and teicoplanin (more resistant BIO+ Colonization than the BIO+ Infection Group). Conclusion: The majority of E. faecium isolates carries high levels of resistance to many antimicrobials, is well equipped with virulence genes, and possesses the ability to form biofilm.

Klebsiella pneumoniae infections have always been an important problem in public health, but today, the increasing resistance of these bacteria to antibiotics due to β-lactamases production has renewed interest in K. pneumoniae infections. The aim of the study was to present a case of a neurosurgical patient with multidrug-resistant K. pneumoniae ST11 infection after craniectomy. Four K. pneumoniae isolates from various clinical materials of the patient undergone identification and susceptibility testing with the Vitek2 system. Tests for β-lactamases production were performed according to EUCAST guidelines. Strains were analyzed for bla genes responsible for β-lactamase production (blaTEM, blaSHV, blaCTX-M, blaVIM, blaIMP, blaNDM, blaKPC, blaOXA-48) using PCR. Moreover, the genetic relatedness of these isolates was determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). All tested strain presented multidrug resistance. The highest susceptibility was observed for imipenem, meropenem, and ertapenem. The strain isolated from the nervous system was ESBL-positive with blaSHV-11, blaTEM-1, and blaCTX-M-15 genes. Additionally, the strain from urine was blaKPC-3-positive. Molecular typing revealed that all strains belonged to the same clone and identified two PFGE profiles. The analysis of MLST allelic profile showed that tested K. pneumoniae strains belonged to ST11. Identification of ST11 K. pneumoniae as etiological factor of infection unfavorably impacts on prognosis among neurosurgical patient after craniectomy.

The combination of an antifungal agent and drug carrier with adjunctive antimicrobial properties represents novel strategy of complex therapy in pharmaceutical technology. The goal of this study was to investigate the unmodified and ion cross-linked chitosan’s influence on anti-Candida activity of clotrimazole used as a model drug in hydrogels. It was particularly crucial to explore whether the chitosans’ structure modification by β-glycerophosphate altered its antifungal properties. Antifungal studies (performed by plate diffusion method according to CLSI reference protocol) revealed that hydrogels obtained with chitosan/β-glycerophosphate displayed lower anti-Candida effect, probably as a result of weakened polycationic properties of chitosan in the presence of ion cross-linker. Designed chitosan hydrogels with clotrimazole were found to be more efficient against tested Candida strains and showed more favorable drug release profile compared to commercially available product. These observations indicate that novel chitosan formulations may be considered as promising semi-solid delivery system of clotrimazole.

Purpose Strains of Acinetobacter spp. are responsible for a considerable percentage of hospital infections. These pathogens have colonized hospital environment and developed resistance to many currently available antibiotics. The aim of this study was one year-long analysis of the occurrence of multiresistant strains of Acinetobacter spp. in population of patients hospitalized in ICU of ED and determination of their genetic similarity. Material/Methods Subject of research was the population of patients admitted to ED of University Hospital in Bialystok in the period from 01.08.2010 to 01.08.2011. In the analysed group of patients, infections were identified on the basis of the guidelines of CDC. Identification and drug susceptibility of strains was specified using the automatic methods with the analyzer Vitek 2XL. Genotyping using Rep-PCR method in DiversiLab system was performed on strains of Acinetobacter spp. to determinate their genetic similarity. Results During analyzed period 405 patients were hospitalized, from 14 of them multiresistant strains of Acinetobacter spp. were isolated. Conducted genetic research allowed to detect 5 clones. Rep-PCR method in DiversiLab system enabled to learn that different clone of multiresistant strain of Acinetobacter spp. is responsible for variable forms of infection. Conclusions Results of conducted research suggest that genotyping with rep-PCR method in DiversiLab system is useful tool in diagnostics of clones of multiresistant pathogens isolated from patients requiring intensive care, hospitalized in ED. Genotyping with rep-PCR method combined with epidemiological investigation enables to establish ways of spreading of multiresistant strains of Acinetobacter spp. in ED.

Purpose Over the past years, an increase in resistance to aminoglycosides has been observed among Enterobacteriaceae rods. This resistance development reduces therapeutic options for infections caused by multidrug-resistance organisms. Because of the changing epidemiology of extended-spectrum β-lactamases (ESBLs) and resistance to aminoglycosides, we investigated the prevalence of the aac(3)-Ia, aac(6′)-Ib, ant(4′)-IIa, ant(2”)-Ia, and aph(3”)-Ib genes encoding aminoglycoside-modifying enzymes (AMEs) in ESBL-producing Escherichia coli as well as ESBL-non-producing isolates. To understand bacterial resistance to aminoglycoside antibiotics, we estimated resistance phenotypes and the presence of genes responsible for this resistance. Materials and methods The study was conducted on 44 E.coli strains originated from patients hospitalized at University Hospital of Bialystok. MIC values were obtained for gentamicin, amikacin, netilmicin, and tobramycin. Isolates were tested for the presence of the aac(3)-Ia, aac(6′)-Ib, ant(4′)-IIa, ant(2”)-Ia, and aph(3”)-Ib genes with the use of the PCR technique. Results Resistance to aminoglycosides was found in 79.5% of the isolates. The highest percentages of resistance were observed for tobramycin (70,5%) and gentamicin (59%), followed by netilmicin (43.2%) and amikacin (11.4%). PCR assays revealed the presence of aac(6′)-Ib among 26 (59.2%) strains, aph(3”)-Ib among 16 (36.2%), aac(3)-Ia among 7 (15.9%), and ant(2”)-Ia among 2 (4.6%) strains. Conclusions The enzymatic resistance against aminoglycosides in northeastern Poland among clinical isolates of E. coli is predominantly caused by aac(6′)-Ib and aph(3”)-Ib. Amikacin may be used for therapy of infections caused by ESBL-producing E. coli, because of the low rates of resistance.

More and more is known about the role of venous wall abnormalities and valvular incompetence in the development of chronic venous disorders (CVD). Unfortunately detailed mechanisms of CVD pathophysiology are not well understood. Recent studies focus on involvement of the inflammatory process in the structural remodeling of venous valves and venous wall. The aim of this study is to investigate and to document the memory T cells homeostasis in CVD patients. In this study we present lymphocytic changes in blood from varicose veins in terms of total CD4+ and CD8+ T cells and their particular subsets of memory T cells: TN, TCM and TEM. Results suggest that immunological memory may be involved in the CVD development.

T cell memory in comparison with B cell memory is not well understood. This review focuses on CD8+ and CD4+ memory T cells. In this article we try to define memory cells and also present models of memory T cells formation. We would also like to delineate their differentiation into distinct subsets. Long-lived memory T cells consist in two main subsets: TCM and TEM. Recent studies have shown that not all cells considered to be memory cells differentiate into TCM and TEM, but a small proportion of theses cells exhibit naive cells phenotype. Memory T cells constitute a heterogeneous population of cells. In this study we lay stress on characteristic of main memory T cells subsets and their alleged participation in immune response upon reexposure to the Ag.

An increase in the antibiotic resistance among members of theEnterobacteriaceaefamily has been observed worldwide. Multidrug-resistant Gram-negative rods are increasingly reported. The treatment of infections caused byEscherichia coliand otherEnterobacteriaceaehas become an important clinical problem associated with reduced therapeutic possibilities. Antimicrobial carbapenems are considered the last line of defense against multidrug-resistant Gram-negative bacteria. Unfortunately, an increase of carbapenem resistance due to the production ofKlebsiella pneumoniaecarbapenemase (KPC) enzymes has been observed. In this study we describe the ability ofE. colito produce carbapenemase enzymes based on the results of the combination disc assay with boronic acid performed according to guidelines established by the European Community on Antimicrobial Susceptibility Testing (EUCAST) and the biochemical Carba NP test. Moreover, we evaluated the presence of genes responsible for the production of carbapenemases (blaKPC,blaVIM,blaIMP,blaOXA-48) and genes encoding otherβ-lactamases (blaSHV,blaTEM,blaCTX-M) amongE. coliisolate. The tested isolate ofE. colithat possessed theblaKPC-3andblaTEM-34genes was identified. The tested strain exhibited susceptibility to colistin (0.38 μg/mL) and tigecycline (1 μg/mL). This is the first detection ofblaKPC-3in anE. coliST479 in Poland.

Most vaccine modalities for human immunodeficiency virus type 1 (HIV-1) tested for immunogenicity and efficacy in the SIVmac (simian immunodeficiency virus) macaque model do not include the viral regulatory proteins. Because viral regulatory proteins are expressed early during the virus life cycle and represent an additional source of antigens, their inclusion as a vaccine component may increase the overall virus-specific immune response in vaccinees. However, at least two of the early proteins, Tat and Nef, may be immunosuppressive, limiting their usefulness as components of an SIV vaccine. We have constructed a polyvalent chimeric protein in which the open reading frames for Tat and Nef have been reassorted and the nuclear localization sequence for Tat and Rev and the myristoylation site for Nef have been removed. The resulting DNA plasmid (pDNA-SIV-Retanef) (pDNA-SIV-RTN) encodes a protein of 55 kDa (Retanef) that localizes at the steady state in the cytoplasma of transfected cells. Both the DNA-SIV-RTN and the highly attenuated recombinant poxvirus vector NYVAC-SIV-RTN were demonstrated to be immunogenic in SIVmac251-infected macaques treated with ART as well as in naive macaques. An equivalent strategy may be used for the generation of polyvalent antigens encoding the regulatory proteins in a HIV-1 vaccine candidate.

The growing incidence of multidrug resistance (MDR) in bacteria is an emerging challenge in the treatment of infections. Acinetobacter baumannii is an opportunistic pathogen prone to exhibit MDR that contributes significantly to nosocomial infections, particularly in severely ill patients. Thus, we performed research on rifampicin activity against selected MDR OXA-72 carbapenemase-producing A. baumannii strains. Since it is widely accepted that rifampicin should not be used as monotherapy in order to avoid the rapid development of rifampicin resistance, we evaluated the efficacy of combination therapy with imipenem.Minimal inhibitory concentrations (MICs) of both rifampicin and imipenem were determined by use of the broth microdilution method. Evaluations of the interactions between rifampicin and imipenem were performed by analysis of the fractional inhibitory concentration index (∑FIC), determined using the checkerboard titration method.All tested isolates showed full susceptibility to rifampicin. The checkerboard method revealed synergism in 5 isolates (29%) and an additive effect in another 5 isolates (29%); no difference was reported in the remaining 7 isolates (41%). Strains moderately resistant to imipenem (MIC ≤ 64 mg/l) tended to show synergy or additive interaction.We conclude that in vitro synergism or an additive interaction between rifampicin and imipenem most likely occurs in A. baumannii strains showing moderate resistance to imipenem (MIC ≤ 64 mg/l). Moreover, utilizing this combination in the therapy of infections caused by strains exhibiting higher levels of resistance (MIC64 mg/l) is not recommended since in this setting imipenem could not prevent the development of rifampicin resistance.

Acinetobacter baumannii has emerged as a highly problematic hospital-associated pathogen. Different mechanisms contribute to the formation of multidrug resistance in A. baumannii, including the AdeABC efflux system. Distribution of the structural and regulatory genes encoding the AdeABC efflux system among genetically diverse clinical A. baumannii strains was achieved by using PCR and pulsed-field gel electrophoresis techniques. The distribution of adeABRS genes is extremely high among our A. baumannii strains, except the adeC gene. We have observed a large proportion of strains presenting multidrug-resistance phenotype for several years. The efflux pump could be an important mechanism in these strains in resistance to antibiotics.

Summary Significant changes in the frequency of candidaemia and the distribution of causative species have been noted worldwide in the last two decades. In this study, we present the results of the first multicentre survey of fungaemia in Polish hospitals. A total of 302 candidaemia episodes in 294 patients were identified in 20 hospitals during a 2-year period. The highest number of infections was found in intensive care (30.8%) and surgical (29.5%) units, followed by haematological (15.9%), ‘others’ (19.2%) and neonatological (4.6%) units. Candida albicans was isolated from 50.96% of episodes; its prevalence was higher in intensive care unit and neonatology (61.22% and 73.33%, respectively), and significantly lower in haematology (22%; P

The aim of this study was to investigate the prevalence of the aacA4 gene in a population of multidrug resistant strains of P. aeruginosa isolated from bronchial secretions obtained from the Intensive Therapy Unit (ITU). Twelve MDR isolates were tested for antibiotic susceptibility and the presence of the aacA4 gene. In this study, 58.3% of the strains contained (6’)-Ib’ aminoglycoside acetyltransferase gene. All of the studied strains (aacA4-positive and aacA4-negative) were susceptible only to colistine (100%). Among other antibiotics, the lowest resistance rates were those shown against ceftazidime (14.3% to 20%) and imipenem (28.6% to 40%). Our studies frequently revealed the presence of the aacA4 gene as a factor responsible for resistance; it is probable that other mechanisms of resistance to aminoglycoside antibiotics also occurred.

Acinetobacter baumannii plays an increasing role in the pathogenesis of infections in humans. The bacilli are frequently isolated from patients treated in intensive care units. A growing resistance to antibiotics is leading to the emergence of strains that are multidrug-resistant and resistant to all available agents. The objective of this study was to assess susceptibility to antibiotics and to determine the presence and current level of the extended-spectrum β-lactamases (ESBLs) and attempt to isolate the Acinetobacter baumannii strain carrying the bla PER gene. A total of 51 strains of A. baumannii identified by phenotypic features were examined. That the strains belonged to the species was confirmed by the presence of the bla OXA-51-like ; gene. A broth microdilution method was used for antibacterial susceptibility testing. The occurrence of ESBLs was determined using phenotypic double-disk synergy tests. The PCR technique was used to confirm the presence of the bla PER-1 ; gene encoding ESBL. The most active antibiotics were meropenem, cefepime and ampicillin/sulbactam, with susceptibility shown by 76.5%, 60.8% and 56.9% of the strains, respectively. The strains exhibited the highest resistance (> 75%) to piperacillin, tetracycline, ciprofloxacin and cefotaxime. Phenotypic tests revealed ESBL mechanism of resistance in approximately 20% of Acinetobacter baumannii isolates. However, the PCR technique did not confirm the presence of the bla PER-1 ; gene in any of the Acinetobacter baumannii strains examined in our hospital. Acinetobacter baumannii strains demonstrate considerable resistance to many groups of antibiotics. Our findings indicate the involvement of enzymes belonging to families other than PER β-lactamase in resistance to β-lactams in A. baumannii.

Extended spectrum β-lactamases production is one of the most common mechanism of resistance to extended spectrum β-lactam antibiotics is increasing worldwide. Twenty five strains of Klebsiella pneumoniae isolated from clinical specimens were tested. Based on the phenotypic confirmatory test all these strains were defined as ESBL producers named ESBL(+). The plasmid DNA from each strains was used to investigate the presence of blaSHV genes responsible for extended spectrum β-lactamases production. Moreover, susceptibility of these strains to antibiotic other than β-lactams in was tested.

The aim of this study was to evaluate the presence of aac(6')-Ib gene conferring resistance to aminoglycosides in Proteus mirabilis strains. Five isolates had aac(6')-Ib gene. In one case the gene was no-expressed. Three isolates were resistant to all aminoglycosides and minimum inhibitory concentrations were > or = 256 microg/ml. Additionally, all positive strains were resistant to tetracycline and ciprofloxacin.

Acinetobacter baumannii is an opportunistic pathogen which play the more and more greater role in the pathogenicity of the human. It is often attached with the hospital environment, in which is able easily to survive for many days even in adverse conditions. Acinetobacter baumannii is the species responsible for a serious nosocomial infections, especially in the intensive care units. Option of surviving in natural niches, and in the hospital environment could also be associated with the efflux pump mechanisms. Mechanisms of efflux universally appear in all cells (eukaryotic and prokaryotic) and play the physiological important role. In prokaryote, the main functions are evasion of such naturally produced molecules, removal of metabolic products and toxins. These pumps could also be involved in an early stage of infection, such as adhesion to host cells and the colonization. Importantly, they remove commonly used antibiotics from the cell in therapy of infections caused by these bacteria. Efflux pumps exemplify a unique phenomenon in drug resistance: a single mechanism causing resistance against several different classes of antibiotics. In Acinetobacter baumannii, the AdeABC efflux pump, a member of the resistance-nodulation-cell division family (RND), has been well characterized. Aminoglicosides, tetracyclines, erythromycin, chloramphenicol, trimethoprim, fluoroquinolones, some beta-lactams, and also recently tigecycline, were found to be substrates for this pump. Drugs, as substrates for the AdeABC pump, can increase the expression of the AdeABC genes, leading to multidrug resistance (MDR). From this reason, treatment failure and death caused by Acinetobacter baumannii infections or underlying diseases are common. Because the AdeABC pump is widespread in Acinetobacter baumannii, similarly to other pumps in Gram-negative and Gram-positive bacteria, exists a need of searching a new therapeutic solutions. Specific efflux inhibitors of pumps (EPIs), including AdeABC inhibitors, could be suppress the activity of pumps and restore the sensitivity of such important bacteria as Acinetobacter baumannii to commonly used antibiotic.

The aim of this study was to determine the antibacterial and antifungal properties of the extracts, subextracts and essential oils of Bidens tripartita flowers and herbs. In the study, twelve extracts and two essential oils were investigated for activity against different Gram-positive Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Gram-negative bacteria Escherichia coli, E. coli (beta-laktamase+), Klebsiella pneumoniae (ESBL+), Pseudomonas aeruginosa and some fungal organisms Candida albicans, C. parapsilosis, Aspergillus fumigatus, A. terreus using a broth microdilution and disc diffusion methods. The results obtained indicate antimicrobial activity of the tested extracts (except butanolic extracts), which however did not inhibit the growth of fungi used in this study. Bacteriostatic effect of both essential oils is insignificant, but they have strong antifungal activity. These results support the use of B. tripartita to treat a microbial infections and it is indicated as an antimicrobial and antifungal agent, which may act as pharmaceuticals and preservatives.

Staphylococcus aureus obtained from a University Hospital in Poland were characterized in relation to resistance to aminoglycoside antibiotics and the distribution of the genes encoding the most clinically relevant aminoglycoside modifying enzymes (AMEs). Of a total of 118 S. aureus, 45 (38.1%) isolates were found to be resistant to at least one of the tested antibiotics. All aminoglycoside resistant isolates except one 44 (97.8%) were resistant to kanamycin. The majority of strains 37 (82.2%) and 32 (71.1%) expressed resistance to neomycin and tobramycin, respectively. Eleven strains (24.4%) were resistant to gentamicin or amikacin. All S. aureus strains were sensitive to netilmicin. The most prevalent resistance gene was aac(6')-Ie+aph(2') found in 13 (28.9%) strains and 12 (26.7%) isolates carried ant(4')-Ia gene, whilst aph(3')-IIIa gene was detected in only 7 (15.6%) isolates. Additionally, the ant(6)-Ia and str genes were detected in 14 (31.1%) and 2 (4.4%) strains, respectively. Ten (22.2%) strains resistant to amikacin, tobramycin, kanamycin or neomycin did not harbor any of the above-noted genes.

Since about twenty years, following the introduction into therapeutic of news beta-lactam antibiotics (broad-spectrum cephalosporins, monobactams and carbapenems), a very significant number of new beta-lactamases appeared. These enzymes confer to the bacteria which put them, the means of resisting new molecules. The genetic events involved in this evolution are of two types: evolution of old enzymes by mutation and especially appearance of new genes coming for some, from bacteria of the environment. Numerous mechanisms of enzymatic resistance to the carbapenems have been described in Pseudomonas aeruginosa. The important mechanism of inactivation carbapenems is production variety of b-lactam hydrolysing enzymes associated to carbapenemases. The metallo-beta-enzymes (IMP, VIM, SPM, GIM types) are the most clinically significant carbapenemases. P. aeruginosa posses MBLs and seem to have acquired them through transmissible genetic elements (plasmids or transposons associated with integron) and can be transmission to other bacteria. They have reported worldwide but mostly from South East Asia and Europe. The enzymes, belonging to the molecular class B family, are the most worrisome of all beta-lactamases because they confer resistance to carbapenems and all the beta-lactams (with the exception of aztreonam) and usually to aminoglycosides and quinolones. The dissemination of MBLs genes is thought to be driven by regional consumption of extended--spectrum antibiotics (e.g. cephalosporins and carbapenems), and therefore care must be taken that these drugs are not used unnecessarily.