Fecal microbiota transplantation - methods of treatment of recurrent Clostridium difficile infections and other diseases.

Clostridium difficile is a serious epidemiological problem and particularly dangerous microorganism causing hospital infections. Currently, the treatment of C. difficile infections is the use of metronidazole or vancomycin. However, in some patients, recurrent infection difficult to treat occurs. Fecal microbiota transplantation (FMT) is a new method used to treat the recurrent CDI. FMT consists in the infusion of the fecal suspension from a healthy donor into the gastrointestinal tract of a patient with CDI to restore the natural intestinal microflora. FMT is safe and effective treatment of recurrent CDI. FMT is extensively described around the world, but to date only two randomized studies confirming the effectiveness of FMT have been conducted. This method was also applied in the treatment of diseases such as pseudomembranous colitis, ulcerative colitis, Crohn's disease and irritable bowel syndrome. The review describes the procedure for FMT and the current state of knowledge about the effectiveness of FMT in the treatment of recurrent CDI.

Correlation between the number of Pro-Ala repeats in the EmrA homologue of Acinetobacter baumannii and resistance to netilmicin, tobramycin, imipenem and ceftazidime.

Acinetobacter baumannii coccobacilli are dangerous to patients in intensive care units because of their multidrug resistance to antibiotics, developed mainly in the past decade. This study aimed to examine whether there is a significant correlation between the number of Pro-Ala repeats in the CAP01997 protein, the EmrA homologue of A. baumannii, and resistance to antibiotics. A total of 79 multidrug-resistant A. baumannii strains isolated from patients were analysed. Resistance to antibiotics was determined on Mueller-Hinton agar plates using the Kirby-Bauer disk diffusion method. The number of CCTGCA repeats encoding Pro-Ala repeats in CAP01997 was determined by PCR and capillary electrophoresis. The 3D models of CAP01997 containing Pro-Ala repeats were initially generated using RaptorX Structure Prediction server and were assembled with EasyModeller 4.0. The models were embedded in a model bacterial membrane based on structural information from homologous proteins and were refined using 100-ns molecular dynamics simulations. The results of this research show significant correlation between susceptibility to netilmicin, tobramycin and imipenem and the number of repeated Pro-Ala sequences in the CAP01997 protein, a homologue of the Escherichia coli transporter EmrA. Predicted structures suggest potential mechanisms that confer drug resistance by reshaping the cytoplasmic interface between CAP01997 protein and the critical component of the multidrug efflux pump homologous to EmrB. Based on these results, we can conclude that the CAP01997 protein, an EmrA homologue of A. baumannii, confers resistance to netilmicin, tobramycin and imipenem, depending on the number of Pro-Ala repeats.

Prediction of antifungal activity of gemini imidazolium compounds.

The progress of antimicrobial therapy contributes to the development of strains of fungi resistant to antimicrobial drugs. Since cationic surfactants have been described as good antifungals, we present a SAR study of a novel homologous series of 140 bis-quaternary imidazolium chlorides and analyze them with respect to their biological activity against Candida albicans as one of the major opportunistic pathogens causing a wide spectrum of diseases in human beings. We characterize a set of features of these compounds, concerning their structure, molecular descriptors, and surface active properties. SAR study was conducted with the help of the Dominance-Based Rough Set Approach (DRSA), which involves identification of relevant features and relevant combinations of features being in strong relationship with a high antifungal activity of the compounds. The SAR study shows, moreover, that the antifungal activity is dependent on the type of substituents and their position at the chloride moiety, as well as on the surface active properties of the compounds. We also show that molecular descriptors MlogP, HOMO-LUMO gap, total structure connectivity index, and Wiener index may be useful in prediction of antifungal activity of new chemical compounds.

Catheter-related blood stream infection caused by Raoultella ornithinolytica.

Raoultella spp. representatives are Gram-negative capsulated, nonmotile rods. These bacteria are found in the natural environment: plants, water, soil and insects. R. ornithinolytica is one of the three species of Raoultella. R. ornithinolytica is the only species within the genus which has the ability to produce ornithine decarboxylase. Human infections related to R. ornithinolytica are exceedingly rare. The present case report describes catheter-related blood stream infection caused by R. ornithinolytica and successfully treated with antibiotic therapy.

Proteus mirabilis biofilm - Qualitative and quantitative colorimetric methods-based evaluation

Proteus mirabilis strains ability to form biofilm is a current topic of a number of research worldwide. In this study the biofilm formation of P. mirabilis strains derived from urine of the catheterized and non-catheterized patients has been investigated. A total number of 39 P. mirabilis strains isolated from the urine samples of the patients of dr Antoni Jurasz University Hospital No. 1 in Bydgoszcz clinics between 2011 and 2012 was used. Biofilm formation was evaluated using two independent quantitative and qualitative methods with TTC (2,3,5-triphenyl-tetrazolium chloride) and CV (crystal violet) application. The obtained results confirmed biofilm formation by all the examined strains, except quantitative method with TTC, in which 7.7% of the strains did not have this ability. It was shown that P. mirabilis rods have the ability to form biofilm on the surfaces of both biomaterials applied, polystyrene and polyvinyl chloride (Nelaton catheters). The differences in ability to form biofilm observed between P. mirabilis strains derived from the urine of the catheterized and non-catheterized patients were not statistically significant.

The prevalence of infections and colonisation with Klebsiella pneumoniae strains isolated in ICU patients.

BACKGROUND: Klebsiella spp. are among the bacteria most commonly isolated from patients with infections in ICUs. The source of these infections may be the microflora of the patient or the hospital environment. Increasingly, Klebsiella strains are also being isolated from epidemic outbreaks. This situation is largely the result of widespread, irrational antibiotic use, the virulence of the bacterial strains and their ability to survive in the hospital environment. The purpose of this dissertation was to estimate the prevalence of Klebsiella pneumoniae strains isolated from patients hospitalised in a single ICU. METHODS: Seventy-eight isolates of K. pneumoniae were studied. The identification and the susceptibility to selected antibiotics were tested by an automated system, VITEK2 Compact. For the analysed strains, the production of different beta-lactamases was noted. RESULTS: Production of ESBL was detected in 64.1% of the K. pneumoniae strains isolated from infections and 74.4% from rectal swabs. Most of the strains were susceptible to imipenem (97.7%) and meropenem (96.1%). Sixty-nine (57.0%) of the analysed strains were identified as multidrug resistant. CONCLUSION: Most of the analysed Klebsiella pneumoniae strains produced ESBL-beta-lactamases. The frequency of colonisation and infection with multidrug resistant strains of K. pneumoniae in patients hospitalised in the ICU is very high.

The use of the HRM method for identifying possible mutations in the ymoA gene region and evaluating their influence on the enterotoxic properties of Y. enterocolitica strains.

BACKGROUND: The yst gene that encodes the production of Yst enterotoxins is one of the most important and reliable virulence markers. Its ability to produce Yst has been demonstrated in pathogenic strains isolated from clinical cases of yersiniosis with diarrhea. However, not all yst positive strains produce enterotoxins. According to some authors, Yst production can be restored in a silent strain by ymoA mutation. In this study, the HRM method was applied to identify ymoA single nucleotide polymorphism with the aim of evaluating their influence on the enterotoxic properties of Y. enterocolitica strains. RESULTS: Two genotypes (A and G) of the examined nucleotide sequence and some variations were detected in the HRM analysis. A phylogenetic analysis of 10 genotype A nucleotide sequences revealed 100% similarity with the Yersinia enterocolitica subsp. enterocolitica 8081 genome NCBI Acc. No. AM286415. An analysis of 10 genotype G nucleotide sequences and 3 variations sequences revealed two point mutations in the examined region: transition A3387326G and insertion A in position 3387368. However, no mutations were observed in the coding region of any of the examined ymoA gene fragments. Genotype G was identified in nearly all Y. enterocolitica strains isolated from pigs. Only 4 nucleotide sequences were similar to AM286415 and did not feature point mutations. In case of human Y. enterocolitica strains 31 were classified as belonging to genotype A, the remaining 59 belonged to genotype G and were characterized by the presence of point mutations. CONCLUSIONS: No correlations were observed between enterotoxic properties and the presence of mutations in the ymoA gene region of Y. enterocolitica strains isolated from both humans and pigs.

Synthesis, in vitro biological screening and molecular docking studies of novel camphor-based thiazoles.

Synthesis, characterization and investigation of antibacterial and antifungal activities of twelve camphor based 2,4-disubstituted 1,3-thiazoles is presented. Their structures were determined using NMR, IR, FAB MS and HRMS analyses. Among the derivatives, 3i and 5 were found to exhibit antifungal and antibacterial activities comparable to that of fluconazole and ciprofloxacin against yeast belonging to Candida spp., MIC 0.12-0.98 µg/ml and Gram-positive bacteria including both pathogenic S. aureus and opportunistic S. epidermidis, MIC 0.98-7.81 µg/ml, B. subtilis and B. cereus, MIC 3.91-31.25 µg/ml, and M. luteus, MIC 0.98 µg/ml species, respectively. Molecular docking studies of all compounds into the active sites of microbial enzymes indicated a possible targets SAP and NMT, thiazoles 3a-j, 4, 5 showed more favourable affinity than the native ligand.

Comparison of detection methods for extended-spectrum beta-lactamases in Escherichia coli strains.

INTRODUCTION: Detection of extended-spectrum beta-lactamases (ESBLs) could be a major challenge for microbiologists--the difficulties arise mainly from the phenotypic differences among strains. MATERIALS AND METHODS: Evaluation of ESBLs was performed on 42 strains of E. coli by: 1) DDST on MHA, 2) DDST on MHA with cloxacillin, 3) CT on MHA, according to CLSI, 4) CT on MHA with cloxacillin, 5) Etest ESBL (AB Biodisk), 6) CHROMagarTM ESBL (GRASO), 7) ChromID® ESBL (bioMérieux), and 8) automatic system VITEK2 ESBL test (bioMérieux). RESULT: Positive results were obtained for 20 strains using method 1, for 18 strains using method 2, 17 by method 3, 14 by method 4, 11 by method 5, 39 by method 6, 40 by method 7, and 15 by method 8. Using Etest ESBL 6.0 non-determinable results were obtained. The most consistent results were obtained when comparing the results of method 3 with results of method 2 (97.6%), and comparing the results obtained using methods 3 and 8 (95.2%). CONCLUSIONS: Based on our study we conclude that the chromogenic media can only be used as a screening method for the detection of ESBLs in E. coli rods. Etest is less useful compared to other phenotype methods, due to the impossibility of obtaining results for all the tested strains. Adding cloxacillin to MHA does not increase the frequency of detection of ESBLs in E. coli strains. DDST seems to be the most reliable among phenotypic methods for the detection of ESBLs in E. coli rods.

Detection of K1 antigen of Escherichia coli rods isolated from pregnant women and neonates.

The K1 antigen is an important virulence determinant of Escherichia coli strains and has been shown to be associated particularly with neonatal meningitis, bacteraemia and septicaemia. Thus, its detection seems to be useful, especially in the case of E. coli strains isolated from pregnant women and newborns. In this study, the sensitivity and specificity of the latex agglutination test (Pastorex Meningitis) for identification of E. coli serogroup K1 were assessed, using PCR as the gold standard. Our results showed that consistency of results between latex agglutination test and PCR amounted to 98.5%. Therefore, Pastorex Meningitis is a good alternative to PCR and could be used for rapid K1 antigen detection, especially in local non-specialized laboratories with limited resources where PCR assay is not applied.

In vitro effect of amphotericin B on Candida albicans, Candida glabrata and Candida parapsilosis biofilm formation.

Candida spp. biofilm is considered highly resistant to conventional antifungals. The aim of this study was to investigate the in vitro effect of amphotericin B on Candida spp. biofilms at different stages of maturation. We investigated the activity of amphotericin B against 78 clinical isolates of Candida spp., representing three species, growing as planktonic and sessile cells, by a widely accepted broth microdilution method. The in vitro effect on sessile cell viability was evaluated by MTT reduction assay. All examined strains were susceptible to amphotericin B when grown as free-living cells. At the early stages of biofilm maturation 96.7-100.0 % strains, depending on species, displayed amphotericin B sessile minimal inhibitory concentration (SMIC) ≤ 1 µg/mL. Mature Candida spp. biofilm of 32.1-90.0 % strains displayed amphotericin B SMIC ≤ 1 µg/mL. Based on these results, amphotericin B displays species- and strain-depending activity against Candida spp. biofilms.

Antimicrobial activity and SAR study of new gemini imidazolium-based chlorides.

A series of 70 new 3,3'(α,ω-dioxaalkyl)bis(1-alkylimidazolium) chlorides were synthesized. They were characterized with respect to surface active properties and antimicrobial activity against the following pathogens: Staphylococcus aureus, Enterococcus faecalis, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Candida krusei, and Candida albicans. In this article, besides description of the synthesis, we characterize a set of features of these compounds, concerning their structure (described by the length of the dioxaalkan spacer and the length of the alkyl substituent in the aromatic ring) and surface active properties (critical micelle concentration, value of surface tension at critical micelle concentration, value of surface excess, molecular area of a single particle, and free energy of adsorption of molecule). Then, we present a SAR study for Staphylococcus aureus, as one of the most widespread pathogenic strains, conducted with the help of the Dominance-based Rough Set Approach (DRSA), that involves identification of relevant features and relevant combinations of features being in strong relationship with a high antimicrobial activity of the compounds. The SAR study shows, moreover, that the antimicrobial activity is dependent on the type of substituents and their position at the chloride moiety, as well as on the surface active properties of the compounds.

Proteus mirabilis biofilm - qualitative and quantitative colorimetric methods-based evaluation.

Proteus mirabilis strains ability to form biofilm is a current topic of a number of research worldwide. In this study the biofilm formation of P. mirabilis strains derived from urine of the catheterized and non-catheterized patients has been investigated. A total number of 39 P. mirabilis strains isolated from the urine samples of the patients of dr Antoni Jurasz University Hospital No. 1 in Bydgoszcz clinics between 2011 and 2012 was used. Biofilm formation was evaluated using two independent quantitative and qualitative methods with TTC (2,3,5-triphenyl-tetrazolium chloride) and CV (crystal violet) application. The obtained results confirmed biofilm formation by all the examined strains, except quantitative method with TTC, in which 7.7% of the strains did not have this ability. It was shown that P. mirabilis rods have the ability to form biofilm on the surfaces of both biomaterials applied, polystyrene and polyvinyl chloride (Nelaton catheters). The differences in ability to form biofilm observed between P. mirabilis strains derived from the urine of the catheterized and non-catheterized patients were not statistically significant.

[The evaluation of lipolytic activity of strains of Enterococcus faecium]. / Ocena aktywnosci lipolitycznej szczepów Enterococcus faecium.

INTRODUCTION: Little is known about the involvement of hydrolytic enzymes such as lipases as virulence factors in infections involving Enterococcus spp. METHODS: A total of 45 isolates of E. faecium were investigated. Lipolytic activity of enterococcal strains was determined by Tryptic Soy Agar containing Tween 20, Tween 40, Tween 60, Tween 80 and egg yolk. RESULTS: We detected that E. fecium strains produced lipases more frequently on Tween 20 agar (71.1% strains) than on Tween 40 agar, Tween 60 agar, Tween 80 agar, egg yolk agar (respectively 33.3%, 24.4%, 20.0%, 31.1%). Our results indicate that lipase may be a virulence factor in E. faecium. CONCLUSIONS: Studies suggest that source of isolation from clinical materials (blood, wound and fluid from the abdominal cavity) does not have an influence on the ability hydrolysis esters.

[Evaluation of selected properties of morphological variants of Acinetobacter baumannii complex]. / Ocena wybranych wlasciwosci morfologicznych wariantów paleczek Acinetobacter baumannii complex.

INTRODUCTION: The ability of growth of Acinetobacter baumannii as morphology colony variants have been observed. However, the importance of this phenomenon for its biology is not known. The aim of this study was to evaluate some properties of light and dark morphology colony variants. METHODS: Fifty two isolates were identified by MALDI TOF MS method (MALDI Biotyper, BRUKER). It was evaluated the adhesion to polystyrene and extracellular mucus production of morphology colony variants and its susceptibility to imipenem and meropenem by agar dilution method. RESULTS: Forty eight (92.3%) out of the 52 morphotypes Acinetobacter sp. were identified as A. baumannii, two (5.8%) as A. genomospecies 3, one as the A. calcoaceticus. Sixteen (61.0%) pairs of isolates showed differences in the similarity of the spectra to the spectra of reference strains in the MALDI-TOF MS method. Adhesion to polystyrene was observed in all dark and 92.3% light morphotypes. Extracellular slime was produced by 15 (57.7%) dark morphotypes, and 7 (26.9%) of clear. The differences in susceptibility to imipenem occurred in two (7.7%), and meropenem in three (11.5%) pairs of morphotypes. CONCLUSIONS: The results show diversity of biological properties of morphology colony variants of A. baumannii complex. Differences in the level of adhesion to polystyrene and slime production may indicate the importance of morphological differentiation in virulence of A. baumannii complex.

The assessment of Proteus mirabilis susceptibility to ceftazidime and ciprofloxacin and the impact of these antibiotics at subinhibitory concentrations on Proteus mirabilis biofilms.

Rods of the Proteus genus are commonly isolated from patients, especially from the urinary tracts of the catheterised patients. The infections associated with biomaterials are crucial therapeutic obstacles, due to the bactericidal resistance of the biofilm. The aim of this study was to assess the susceptibility of P. mirabilis planktonic forms to ciprofloxacin and ceftazidime, the ability to form biofilm, and the impact of chosen sub-MIC concentrations of these antibiotics on biofilm at different stages of its formation. The research included 50 P. mirabilis strains isolated from wounds and the urinary tracts from patients of the University Hospital No. 1 in Bydgoszcz. The assessment of susceptibility to ciprofloxacin and ceftazidime was conducted using micromethods. The impact of sub-MIC concentrations of the chosen antibiotics on the biofilm was measured using the TTC method. The resistance to ciprofloxacin was confirmed for 20 strains (40.0%) while to ceftazidime for 32 (64.0%) of the tested P. mirabilis strains. All of the tested strains formed biofilm: 24.0% weakly, 26.0% moderately, and 50.0% strongly. It was determined that ciprofloxacin and ceftazidime caused eradication of the biofilm. Moreover, the connection between origin of the strains, biofilm maturity level, and resistance to antibiotics was proved.

Effects of ceftazidime and ciprofloxacin on biofilm formation in Proteus mirabilis rods.

Proteus mirabilis rods are one of the most commonly isolated species of the Proteus genus from human infections, mainly those from the urinary tract and wounds. They are often related to biofilm structure formation. The bacterial cells of the biofilm are less susceptible to routinely used antimicrobials, making the treatment more difficult. The aim of this study was to evaluate quantitatively the influence of ceftazidime and ciprofloxacin on biofilm formation on the polyvinyl chloride surface by 42 P. mirabilis strains isolated from urine, purulence, wound swab and bedsore samples. It has been shown that ceftazidime and ciprofloxacin at concentrations equal to 1/4, 1/2 and 1 times their MIC values for particular Proteus spp. strains decrease their ability to form biofilms. Moreover, ciprofloxacin at concentrations equal to 1/4, 1/2 and 1 times their MIC values for particular P. mirabilis strains reduces biofilm formation more efficiently than ceftazidime at the corresponding concentration values.

Candidaemia in polish hospitals - a multicentre survey.

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 < 0.001). The frequency of C. krusei and C. tropicalis was significantly higher (24% and 18%) in haematology (P < 0.02); whereas, the distribution of C. glabrata (14.1%) and C. parapsilosis (13.1%) did not possess statistically significant differences between compared departments. Obtained data indicates that species distribution of Candida blood isolates in Polish hospitals reflects worldwide trends, particularly a decrease in the prevalence of infections due to C. albicans.

Usefulness of phenotypic and genotypic methods for metallo-beta-lactamases detection in carbapenem-resistant Acinetobacter baumannii strains.

BACKGROUND: Acinetobacter baumannii is an opportunistic microorganism with an increasing role in nosocomial outbreaks. For the last 2 decades, a growing number of carbapenem-resistant A. baumannii strains have been identified, including the metallo-beta-lactamases (MBLs) producers. The study aimed to investigate the genetic relatedness of, and MBLs production among, a collection of A. baumannii isolates from Poland. MATERIAL/METHODS: This study involved 78 clinical isolates of carbapenem-resistant A. baumannii. Strain typing of the isolates was performed using PCR-RAPD. The presence of MBLs was phenotypically determined using different double disc synergy tests (DDST), the imipenem/EDTA combination disk test (CDT) and Etest MBL. blaIMP and blaVIM genes were detected using a duplex PCR assay. RESULTS: The isolates were divided into 18 PCR-RAPD patterns. Among 18 examined isolates, 94.4% were MBL-positive by the phenotypic method relying on comparing the bacteria growth inhibition zones diameters between imipenem/EDTA and imipenem discs, 88.9% using Etest MBL, 66.7% using the double disc synergy test with ceftazidime, imipenem, meropenem and EDTA, and 88.9% using a corresponding method with 2-MPA. The existence of blaIMP was identified in 8 (10.3%) strains. CONCLUSIONS: MBLs production was an important mechanism of carbapenem resistance among A. baumannii isolates in Poland. Laboratories should routinely screen for MBLs among A. baumannii isolates.

Human meningitis caused by Streptococcus suis.

Streptococcus suis is an important swine pathogen worldwide, which can be transmitted to human beings by direct contact; therefore, S. suis infections occur mainly in people who handle pigs or pork. We present a case of a patient with S. suis meningitis who worked as a butcher in a meat processing plant for 5 years. The 35-year-old man was admitted to the Department of Infectious Diseases in T. Browicz Memorial Central Infectious Disease and Observation Hospital in Bydgoszcz, Poland, with suspected bacterial meningitis. According to his medical history, the patient had been injured during the processing of pork. A microbiological examination of the cerebrospinal fluid and blood revealed S. suis as a single aetiological factor of this infection. The patient was empirically administered cefotaxime (2.0 g at 8-h intervals) and penicillin (9 million U at 8-h intervals). The patient made a complete recovery and his inflammatory markers normalized. Only the hearing deficit of his right ear did not disappear. An otolaryngologist recommended a 4-week steroid therapy. The patient was not examined because he did not report to the clinic. To our knowledge this is the first described case of human meningitis caused by S. suis in Poland.