Insight into the Mechanism of Lysogeny Control of phiCDKH01 Bacteriophage Infecting Clinical Isolate of Clostridioides difficile.

Clostridioides difficile is a causative agent of antibiotic-associated diarrhea as well as pseudomembranous colitis. So far, all known bacteriophages infecting these bacteria are temperate, which means that instead of prompt lysis of host cells, they can integrate into the host genome or replicate episomally. While C. difficile phages are capable of spontaneous induction and entering the lytic pathway, very little is known about the regulation of their maintenance in the state of lysogeny. In this study, we investigated the properties of a putative major repressor of the recently characterized C. difficile phiCDKH01 bacteriophage. A candidate protein belongs to the XRE family and controls the transcription of genes encoding putative phage antirepressors, known to be involved in the regulation of lytic development. Hence, the putative major phage repressor is likely to be responsible for maintenance of the lysogeny.

Antimicrobial Effects of Some Natural Products on Adhesion and Biofilm Inhibition of Clostridioides difficile.

Understanding the potential antimicrobial properties of natural compounds and their impacts on Clostridioides difficile virulence factors may aid in developing alternative strategies for preventing and treating C. difficile infections (CDI). In this study, we investigated the bactericidal effects of ginger oil (GO), peppermint oil (PO), curcumin (CU), cinnamon aldehyde (CI), and trans-cinnamaldehyde (TCI) on the adhesion and biofilm disruption of C. difficile. We used three reference and five clinical C. difficile strains of different ribotypes. The bactericidal activity was assessed using the broth microdilution method. The adhesion was evaluated using human epithelial cell lines, and biofilm formation was visualized by confocal laser scanning microscopy. All tested strains exhibited susceptibility to CU, with minimum inhibitory concentration (MIC) values ranging from 128 µg/mL to 2048 µg/mL. Similarly, all strains were susceptible to CI and TCI, with MIC values ranging from 6.25% (v/v) to 25% (v/v). Most of the tested substances reduced the adhesion of C. difficile strains, while two tested strains showed significantly higher adhesion when co-incubated with the tested substances. Similar observations were made for biofilm formation, with observed density and morphology varied depending on the strain. In conclusion, the tested products demonstrated bactericidal activity and reduced the adhesion of C. difficile strains. They may be considered for further studies as potential antimicrobial agents targeting biofilm-related infections.

The Effect of Subinhibitory Concentration of Metronidazole on the Growth and Biofilm Formation on Toxigenic Clostridioides difficile Strains Belonging to Different Ribotypes.

Clostridioides difficile is a predominant nosocomial pathogen within the healthcare setting able to produce biofilms. Sub-minimum inhibitory concentrations (sub-MICs) of antibiotics trigger mechanisms affecting bacterial virulence, including increased adhesion and biofilm formation. The aim of this study was to investigate how sub-MICs of metronidazole affect the biofilm formation of C. difficile strains. We tested 14 reference and clinical C. difficile strains, including hypervirulent strains of RT027. The MICs of metronidazole for the tested strains were determined using the broth microdilution method. Biofilm formation was evaluated using confocal laser scanning microscopy. The C. difficile strains belonging to RT027 produced the highest amounts of biofilm. The results of confocal laser scanning microscopy showed that all the tested C. difficile strains developed larger biofilms with diversified architectures upon exposure to sub-MICs of metronidazole. In our study, we reveal that sub-MIC concentrations of metronidazole affect the biofilm formation of clinical and reference strains of C. difficile. Importantly, metronidazole induces biofilm formation via hypervirulent RT027 strains.

The Effect of Selected Bee Products on Adhesion and Biofilm of Clostridioides difficile Strains Belonging to Different Ribotypes.

There is an ongoing search for alternative treatments for Clostridioides difficile infections. The aim of the study was to investigate the antibacterial and antibiotic activity of bee products against C. difficile strains with different polymerase chain reaction ribotypes (RTs). The minimum inhibitory concentration (MICs) of Manuka honey 550+, goldenrod honey, pine honey, and bee bread were determined by the broth dilution method. C. difficile adhesion to HT-29, HT-29 MTX, and CCD 841 CoN cell lines was assessed. Biofilm was cultured in titration plates and visualized by confocal microscopy. The MICs of Manuka honey for C. difficile 630 and ATCC 9689 strains and control strain, M 120, were 6.25%, 6.25%, and 1.56% (v/v), respectively; of goldenrod honey, 50%, 50%, and 12.5%, respectively; of pine honey, 25%, 25%, and 25%, respectively; and of bee bread, 100 mg/L, 50 mg/L, and 100 mg/L, respectively. Manuka honey (1%) increased adhesion of C. difficile RT176 strains, and one strain of RT023, to the CCD 841 cell line. Pine honey (1%) increased RT027 adhesion to the HT-29 cell line. Manuka honey, pine honey, and bee bread at subinhibitory concentrations increased the adhesion of C. difficile. Our research proved that bee products are active against the tested strains of C. difficile.

Effect of prebiotics on Bacteroides sp. adhesion and biofilm formation and synbiotic effect on Clostridioides difficile.

Aim: The objective of this study was to determine the effect of standard and candidate prebiotics on the adhesion and biofilm formation of Bacteroides sp. in monoculture and co-culture with Clostridioides difficile. Materials & methods: The effect of seven prebiotics on the adhesion and biofilm formation of Bacteroides sp. to three human cell lines was determined. The effect of Bacteroides sp. and fructooligosaccharides (FOS) on the adhesion and biofilm formation of C. difficile was tested by the co-incubation assay. Results: Inulin, mannose and raffinose presented the best anti-adhesion properties against Bacteroides sp. Combination of Bacteroides sp. with FOS decreased the adhesion of C. difficile. Conclusion: The study shows the potential role of prebiotics and synbiotics in decreasing the burden of C. difficile infections.

The prebiotic effect of human milk oligosaccharides 3'- and 6'-sialyllactose on adhesion and biofilm formation by Clostridioides difficile - pilot study.

Bacterial adhesion is the first stage of colonisation and biofilm formation by Clostridioides difficile. Cell wall proteins (Cwp) 84 and 66 play crucial roles in the pathophysiology of C. difficile and may affect bacterial adhesion. Sialylated human milk oligosaccharides (HMOs) have potential to inhibit bacterial adhesion in vitro. The aim of this study was to investigate how 3'-sialyllactose (SL) and 6'-SL affect adhesion and C. difficile biofilm formation. Also, the influence of these substances on cwp84 and cwp66 genes expression by C. difficile was assessed. An adhesion assay was performed using three human colon cells in vitro, and biofilm formation was evaluated using crystal violet staining and confocal laser scanning microscopy. The effect of 3'-SL and 6'SL on cwp expression was measured using real time-PCR. Both tested HMOs decreased expression of the cwp84 gene, adhesion of C. difficile to human colon cells in vitro and biofilm formation.

Motility and the genotype diversity of the flagellin genes fliC and fliD among Clostridioides difficile ribotypes.

OBJECTIVE: The motility and genotype of the flagellin fliC and fliD genes were investigated in 82 Clostridioides difficile isolates belonging to the ribotypes (RTs): 027 (n = 41), 176 (n = 17), 023 (n = 8), 017 (n = 6) and 046 (n = 10). The reference C. difficile strains 630 and M120 were included as controls for the motility assay. METHODS: A Multiple Locus Variable-number Tandem Repeat Analysis (MLVA) was used to exclude the genetic relatedness of C. difficile isolates belonging to the same RT. The variability of the fliC and fliD genes was determined by PCR-restriction fragment length polymorphism (RFLP) analysis and Sanger sequencing. The motility assay was carried out with 0.175% BHI agar tubes and BHI solid media plates with 0.4% agar. RESULTS: The highest motility was observed in C. difficile RT023 isolates (p < 0.01), followed by RTs 027 and 176. C. difficile isolates of RTs 017 and 046 were less motile than RTs 027, 176 and 023 (p < 0.01). The fliC and fliD genes were present in all clinical isolates irrespective of the motility results. In the fliC gene analysis, four different RFLP groups were identified (I, II, VII, X). The fliC group VII was identified in two RTs (027 and 176), whereas the remaining three groups (I, II and X) belonged to a single RT 046, 017 and 023, respectively. The fliD gene analysis identified four new RFLP groups (a, b, c and d). CONCLUSIONS: C. difficile RT023 is highly motile and its motility is comparable to the hypervirulent RT027 and its genetic relative RT176.

Inhibition of Quinolone- and Multi-Drug-Resistant Clostridioides Difficile Strains by Multi Strain Synbiotics-An Option for Diarrhea Management in Nursing Facilities.

Diarrhea is a common problem in nursing homes. A survey among nursing facilities in Poland was used to characterize diarrhea outbreaks, the burden caused for residents and caregivers and the employed measures. Survey results confirmed that diarrhea is a common problem in nursing homes and in most cases affects groups of residents. The related burden is high or very high for 27% of residents and 40% of caregivers. In 80% of nursing facilities pro or synbiotics are part of the measures used to manage diarrhea. Administration of these kinds of products has been suggested for the management of diarrhea, especially in cases caused by Clostridioides (C.) difficile. C. difficile is one of many potential causes for diarrhea, but is of particular concern for nursing homes because it is responsible for a large proportion of diarrhea outbreaks and is often caused by multi-drug resistant strains. In vitro inhibition of a quinolone-resistant and a multi-drug resistant C. difficile strain was used to evaluate the growth inhibitory effects of commonly used products containing probiotic microorganisms. Growth of both strains was best inhibited by multi-strain synbiotic preparations. These findings suggest that multi-strain synbiotics can be considered as an interventional option for diarrhea caused by C. difficile.

Mortality Following Clostridioides difficile Infection in Europe: A Retrospective Multicenter Case-Control Study.

We aimed to describe the clinical presentation, treatment, outcome and report on factors associated with mortality over a 90-day period in Clostridioides difficile infection (CDI). Descriptive, univariate, and multivariate regression analyses were performed on data collected in a retrospective case-control study conducted in nine hospitals from seven European countries. A total of 624 patients were included, of which 415 were deceased (cases) and 209 were still alive 90 days after a CDI diagnosis (controls). The most common antibiotics used previously in both groups were ß-lactams; previous exposure to fluoroquinolones was significantly (p = 0.0004) greater in deceased patients. Multivariate logistic regression showed that the factors independently related with death during CDI were older age, inadequate CDI therapy, cachexia, malignancy, Charlson Index, long-term care, elevated white blood cell count (WBC), C-reactive protein (CRP), bacteraemia, complications, and cognitive impairment. In addition, older age, higher levels of WBC, neutrophil, CRP or creatinine, the presence of malignancy, cognitive impairment, and complications were strongly correlated with shortening the time from CDI diagnosis to death. CDI prevention should be primarily focused on hospitalised elderly people receiving antibiotics. WBC, neutrophil count, CRP, creatinine, albumin and lactate levels should be tested in every hospitalised patient treated for CDI to assess the risk of a fatal outcome.

The effect of berberine chloride and/or its combination with vancomycin on the growth, biofilm formation, and motility of Clostridioides difficile.

This study aims to investigate the antimicrobial and antibiofilm activity of berberine chloride (BBR) and vancomycin (VAN) as well as synergistic combinations of BBR with VAN against Clostridioides difficile strains. The effect of different concentrations of BBR on strain motility was also assessed. Twelve C. difficile strains (two reference C. difficile 630, ATCC 9689, and one control M120, and 9 clinical C. difficile strains belonging to the PCR-ribotype (RT027)) were collected and investigated for their susceptibility to BBR and VAN in planktonic and biofilm forms. Both the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of BBR for the C. difficile strains were found to vary over a broad range (256-1.024 mg/L and 256-16.384 mg/L, respectively). The MIC and MBC of VAN also varied greatly, ranging from 0.25 to 4.0 mg/L for MIC and 0.25 to 64.0 mg/L for MBC. The synergistic effect of the sub-MIC (1/2 MIC) BBR with VAN reduced of MICs of VAN against the planktonic forms of ten C. difficile strains. The sub-MIC of BBR enhanced the biofilm formation of one strain and was found to be statistically significant. In addition, the sub-MIC of BBR with VAN surprisingly enhanced the biofilm formation of one C. difficile strain. The effect of inhibition of motility in the presence of BBR was statistically significant for 3 clinical strains (p < 0.05). Altogether, BBR exhibited strong antimicrobial activity against C. difficile, and the analysis of the combination of BBR with VAN showed a synergistic effect.

Fructooligosaccharides and mannose affect Clostridium difficile adhesion and biofilm formation in a concentration-dependent manner.

The aim of this study was to investigate the effects that prebiotic and candidates for prebiotics on Clostridium difficile strains to adhere to various human epithelial cell lines and to compare the adhesive properties of specific C. difficile strains. We also sought to examine the effect of different concentrations of fructooligosaccharides and mannose on the formation of biofilms by C. difficile strains. The influence of cellobiose, fructooligosaccharides, inulin, mannose, and raffinose on the adherence properties of various C. difficile strains, including motile 630, non-motile M120, and 10 clinical motile ribotype 027 strains, to non-mucous secreting HT-29, mucous secreting HT-29 MXT, and CCD 841 CoN cells lines. The most effective prebiotics were used in biofilm formation assays. We demonstrated that all C. difficile strains adhered to all cell lines. However, the C. difficile M120 non-motile strain was statistically more likely to adhere to all three cell lines (CFU median, 40) compared to the motile strains (CFU median, 3; p < 0.001). Furthermore, among the carbohydrates examined, only fructooligosaccharides and mannose were found to significantly decrease adhesion (p < 0.001) of C. difficile strains. Alternatively, using a biofilm assay, we observed, via confocal laser scanning microscopy, that sub-inhibitory concentrations (1%) of fructooligosaccharides and mannose functioned to increase biofilm formation by C. difficile. We demonstrated that specific prebiotics and candidate prebiotics exhibit varying anti-adhesive properties towards C. difficile in vitro and that treatment with sub-inhibitory concentrations of prebiotics can cause an increase in biofilm formation by C. difficile.

Clostridium difficile infection: review.

Clostridium difficile (C. difficile) is a Gram-positive, spore-forming, anaerobic bacillus, which is widely distributed in the intestinal tract of humans and animals and in the environment. In the last decade, the frequency and severity of C. difficile infection has been increasing worldwide to become one of the most common hospital-acquired infections. Transmission of this pathogen occurs by the fecal-oral route and the most important risk factors include antibiotic therapy, old age, and hospital or nursing home stay. The clinical picture is diverse and ranges from asymptomatic carrier status, through various degrees of diarrhea, to the most severe, life threatening colitis resulting with death. Diagnosis is based on direct detection of C. difficile toxins in feces, most commonly with the use of EIA assay, but no single test is suitable as a stand-alone test confirming CDI. Antibiotics of choice are vancomycin, fidaxomicin, and metronidazole, though metronidazole is considered as inferior. The goal of this review is to update physicians on current scientific knowledge of C. difficile infection, focusing also on fecal microbiota transplantation which is a promising therapy.

The level of fecal calprotectin significantly correlates with Clostridium difficile infection severity.

INTRODUCTION: Fecal calprotectin (FC) rises significantly in intestinal inflammation accompanied by neutrophil activation - such as Clostridium difficile infection (CDI). The aim of the study was to evaluate the benefit of FC testing in assessing the severity of CDI. MATERIALS AND METHODS: The study group included 76 patients with CDI hospitalized in the Jagiellonian University Hospital in Krakow from July 2017 till January 2018. FC levels were measured using an EIA (Enzyme Immunoassay). Demographic, clinical information and blood tests were recorded using standardized data collection forms. The selection of patients into non-severe and severe groups was carried out in accordance with the ESCMID criteria (European Society of Clinical Microbiology and Infectious Diseases) and some modi cations to those criteria were proposed. RESULTS: the studied population included 76 patients (39 men and 37 women) with CDI aged from 24 to 98 years (mean: 72). Median calprotectin level was 739 (Q25-Q75: 612-799 µg/g), characteristic of patients with colitis. A statistically significant difference in FC concentration in patients with severe vs non-severe CDI was observed (severe - 770 vs non-severe - 659 µg/g, p = 0.009). FC directly correlated with platelets level; however, no correlation between FC level and the blood parameters prognostic for CDI (leukocyte, neutrophil count, albumin, creatinine levels) was found. CONCLUSION: FC level is an indication of ongoing intestinal inflammation in CDI patients. FC level significantly correlated with CDI severity, which demonstrates that FC could serve as a predictive marker for assessing CDI severity.

Hospital-based Clostridium difficile infection surveillance reveals high proportions of PCR ribotypes 027 and 176 in different areas of Poland, 2011 to 2013.

As part of the European Clostridium difficile infections (CDI) surveillance Network (ECDIS-Net), which aims to build capacity for CDI surveillance in Europe, we constructed a new network of hospital-based laboratories in Poland. We performed a survey in 13 randomly selected hospital-laboratories in different sites of the country to determine their annual CDI incidence rates from 2011 to 2013. Information on C. difficile laboratory diagnostic testing and indications for testing was also collected. Moreover, for 2012 and 2013 respectively, participating hospital-laboratories sent all consecutive isolates from CDI patients between February and March to the Anaerobe Laboratory in Warsaw for further molecular characterisation, including the detection of toxin-encoding genes and polymerase chain reaction (PCR)-ribotyping. Within the network, the mean annual hospital CDI incidence rates were 6.1, 8.6 and 9.6 CDI per 10,000 patient-days in 2011, 2012, and 2013 respectively. Six of the 13 laboratories tested specimens only on the request of a physician, five tested samples of antibiotic-associated diarrhoea or samples from patients who developed diarrhoea more than two days after admission (nosocomial diarrhoea), while two tested all submitted diarrhoeal faecal samples. Most laboratories (9/13) used tests to detect glutamate dehydrogenase and toxin A/B either separately or in combination. In the two periods of molecular surveillance, a total of 166 strains were characterised. Of these, 159 were toxigenic and the majority belonged to two PCR-ribotypes: 027 (n=99; 62%) and the closely related ribotype 176 (n=22; 14%). The annual frequency of PCR-ribotype 027 was not significantly different during the surveillance periods (62.9% in 2012; 61.8% in 2013). Our results indicate that CDIs caused by PCR-ribotype 027 predominate in Polish hospitals participating in the surveillance, with the closely related 176 ribotype being the second most common agent of infection.

Occurrence of Clostridium difficile PCR-ribotype 027 and it's closely related PCR-ribotype 176 in hospitals in Poland in 2008-2010.

Since 2003, a rising incidence of Clostridium difficile infection (CDI) in North America and Europe has coincided with outbreaks of C. difficile PCR ribotype 027. This ribotype was not observed in Poland until 2008. In the period 2008-2010, outbreaks of antibiotic-associated diarrhoea occurred in three different hospitals in Poland. Of 30 C. difficile isolates available for microbiological characterisation, 17 (56%) were positive for binary toxin genes and belonged to PCR ribotype 027 (n = 7) and its closely related PCR ribotype 176 (n = 10). All 17 binary toxin-positive C. difficile strains demonstrated high-level resistance to fluoroquinolones (minimum inhibitory concentration (MIC) ≥ 32 mg/L), including ciprofloxacin, gatifloxacin, and moxifloxacin, as well as erythromycin and clindamycin (MIC ≥ 256 mg/L for both). Of 14 patients from whom clinical information was available, 50% had a severe form of CDI, defined by fever (>38.5 °C), decreased kidney function, and high leucocyte count. We conclude that outbreaks of CDI associated with hypervirulent strains belonging to PCR ribotypes 027 and 176 occurred in hospitals in Poland. Further studies evaluating the clinical impact of type 176 are urgently needed.

[Assessment of antagonistic activity in vitro Lactobacillus spp. strains againts Clostridum difficile strains isolated from gastrointestinal tract of patients hospitalized in three hospitals in region Mazovia]. / Ocena antagonistycznego dzialania w warunkach in vitro szczepów z rodzaju Lactobacillus wobec toksynotwórczych szczepów Clostridium difficile wyhodowanych z przewodu pokarmowego pacjentów leczonych w szpitalach na terenie województwa mazowieckiego.

INTRODUCTION: The aim of this study was to evaluate the antagonistic activity of Lactobacillus strains against clinical C. difficile strains isolated from faecal samples of adults patients with diarrhea. A total 61 strains of C. difficile randomly selected isolated in the period 2007-2008 from the gastrointestinal tract of hospitalized patients in three hospitals province Mazovia, Poland. To determination of antagonistic activity ofprobiotic Lactobacillus spp. strains used four reference strains: Lactobacillus plantarum 2017405, Lactobacillus fermentum 353, Lactobacillus acidophilus DSM 21007 and Lactobacillus rhamnosus GG. METHODS: Isolation of C. difficile was performed on selective Columbia agar supplemented with cycloserine/cefoxitine and amphothericin B (CLO medium, bioMérieux, France). The plates were incubated in an anaerobic chamber for 48 h at 37 degrees C. Isolates were identified as C. difficile by the characteristic morphology of the colonies and horse-like odour, green yellow fluorescence under UV. Toxigenicity of of C. difficile strains was determined in PCR to detection of fragments of genes encoding toxin A (tcdA), toxin B (tcdB) and binary toxin (cdtA and cdtB). The study of antagonistic activity four Lactobacillus spp. strains against 61 clinical C. difficile strains was performed according to standard methods. Lactobacillus strains were inoculated on MRS medium and incubated in oxygen-free atmosphere and cut the bars of MRS agar and applied to the plate with cultures of C. difficile strains. RESULTS: Assessment of antagonist activity of Lactobacillus spp. strains was performed by measuring the zone of inhibition of grown of C. difficile strains. The study shows that of probiotic Lactobacillus spp. strains interacted antagonistically in vitro against all toxigenic (A+B+CDT- and A+B+CDT+) of C. difficile strains. CONCLUSIONS: The differences in the antagonistic activity of Lactobacillus spp. strains against different toxigenic clinical C. difficile strains were not observed.

[Assessment of susceptibility of strictly anaerobic bacteria originated from different sources to fluoroquinolones and other antimicrobial drugs]. / Ocena wrazliwosci szczepów bezwzglednych beztlenowców pochodzacych z róznych zródel na fluorochinolony oraz inne leki stosowane w lecznictwie szpitalnym.

INTRODUCTION: During the past 20 years, several studies at a national level in different countries followed resistance trends for Bacteroides sp. and Clostridium difficile. This study analysed antimicrobial susceptibility 73 anaerobic bacteria strains of Bacteroides fragilis group (BFG) and C. difficile to fluoroquinolones and other antimicrobial drugs. METHODS: The strictly anaerobes strains isolated in different hospitals were sent to the Department of Medical Microbiology, Medical Uniwersity of Warsaw, where species determination was carried out with the API20 ANA (bioMerieux SA, Marcy-l'Etoile, France) system. Susceptibility to antimicrobials was determined using E-test. RESULTS: The rates of high resistance to ciprofloxacin and moxifloxacin of BFG was respectively 84% and 31% and among of C. difficile strains respectively 92% and 36%). The percentage of BFG strains resistant to erythromycin and clindamycin were respectively 84% and 46%. The percentage of C. difficile strains resistant to erythromycin and clindamycin was 52%. Reduced level of susceptibility of BFG strains to amoxicillin/clavulanic acid (8%) was confirmed. Resistance to cefoxitin was 16% of BFG strains. All tested strains as well as BFG and C. difficile were susceptible to metronidazole. Was observed reduced leve (EUCAST) of susceptibility of C. difficile strains to vancomycin (13%). CONCLUSIONS. Increasing resistance to various antimicrobial agents is a significant problem in Poland. This demonstrate the need to continue with antibiotic resistance testing and surveys in anaerobic bacteria.

[Assessment of the usefulness of chromogenic medium for the isolation of Clostridium difficile from the gastrointestinal tract of children with diarrhoea]. / Ocena przydatnosci podloza chromogennego do izolacji Clostridium difficile z przewodu pokarmowego dzieci z biegunka.

INTRODUCTION: Clostridium difficile is well known as an important cause of nosocomial infection. Laboratory diagnostics have included bacterial culture or more commonly, direct detection of preformed toxin in stool samples using different assays. The aim of this study was to evaluate and compare two selecitve media to isolation of C. difficile from paediatric diarrhoeal stool samples. METHODS: Fifty nine stool samples, collected from 43 children with diarrhoea, were examined for routine laboratory diagnosis of C. difficile infection. Commercially available tests for detection of A/B toxins of C. difficile were performed. The same stool samples were cultured on two selective media for strain isolation: CLO and CDIFF (bioMerieux S.A., France) and incubated 48h and 24h respectively. RESULTS: Twenty two samples gave positive results for toxins A/B C. difficile. From 24 samples inoculated on selective media C. difficile strains were cultured: from 8 samples on CLO medium and from 16 samples on CDIFF medium. CONCLUSIONS: CDIFF medium is more effective for isolation of C. difficile strains from stool samples collected from children with diarrhoea.

[The impact of UV radiation B and C in vitro on different of bacteria strains isolated from patients hospitalized in the Warsaw Medical University Clinics]. / Wplyw promieniowania uv w zakresie dlugosci b i C, w warunkach in vitro, na rózne szczepy bakterii izolowanych od pacjentów hospitalizowanych w klinikach Warszawskiego Uniwersytetu Medycznego.

INTRODUCTION: Infections in human body caused by various microbes are a significant problem in modern medicine. Special attention is put to infections of wounds, which are a significant threat to the life of patients. Attempts to treat these wounds base mainly on the application of various chemical preparations (locally) and systematic antibiotic treatment. UV radiation, because of its anti-bacterial activity, appear a complementary issue in therapy. AIM OF THE SURVEY: The aim of this study was an examination of the sensitivity of bacteria strains isolated from patients hospitalised in the Warsaw Medical University clinics, and prove that antibiotics and operation of UV B and C radiation with Endolamp 474 may become a complementary or alternative method of treatment. MATERIAL AND METHODOLOGY: The study used 65 strains grown aerobically (15 strains of Escherichia coli, 20 strains of Pseudomonas aeruginosa, 15 strains of Staphylococcus aureus, 15 strains of Streptococcus and Enterococcus sp). The same strains were planted on different excipients and were subjected to UV radiation using Endolamp 474. Correctly prepared strains were radiated from a 25 cm distance in various durations (from 5 seconds to 105 seconds). RESULTS AND CONCLUSIONS: As a result of UV irradiation of microorganisms studied B and C using 474 Endolampy received varied, but the great sensitivity to the effects of this radiation, in all tested bacterial strains. UV radiation on microorganisms requires further study, also in vivo.

Characterization and antimicrobial susceptibility of Clostridium difficile strains isolated from adult patients with diarrhoea hospitalized in two university hospitals in Poland, 2004-2006.

This study analysed 330 Clostridium difficile strains isolated from patients with C. difficile infection who were hospitalized in two university hospitals (H1 and H2) in Warsaw, Poland, over the period 2004-2006. Strains were investigated for the presence of tcdA (A), tcdB (B) and binary toxin (CDT) genes, and antimicrobial susceptibility was determined against nine agents. Among the 330 C. difficile isolates, 150 (45.4 %) were classified as A(+)B(+)CDT(-), 18 (5.5 %) as A(+)B(+)CDT(+), 144 (43.6 %) as A(-)B(+)CDT(-) and 18 (5.5 %) as A(-)B(-)CDT(-). The predominant PCR ribotype in hospitals H1 and H2 was type 017 and accounted for 48.3 and 40.0 %, respectively. Only one PCR ribotype 027 strain was found. The rates of resistance to erythromycin and clindamycin in hospitals H1 and H2 were 53.6 and 53.6 %, and 48.6 and 47.5 %, respectively, whereas resistance rates to the newer fluoroquinolones gatifloxacin and moxifloxacin were 38.5 and 38.5 % (H1) and 38.4 and 40.1 % (H2). Erythromycin resistance was frequently associated with resistance to clindamycin and newer fluoroquinolones in strains belonging to type 017. No metronidazole- and vancomycin-resistant isolates were found, although two C. difficile isolates had elevated MIC values of metronidazole (MIC range 1.0-1.5 mg l(-1)) and 15 strains revealed elevated MIC values for vancomycin (MIC range 1.5-2.0 mg l(-1)). In conclusion, an increase in non-027 CDT-producing C. difficile strains was observed in Poland, but C. difficile PCR ribotype 017 remains a major circulating type.