Background: It is not clear which species of bacteria may be involved in inflammatory bowel disease (IBD). One way of determining which bacteria might be likely candidates is to use culture-independent methods to identify microorganisms that are present in diseased tissues but not in controls. Aims: (1) To assess the diversity of microbial communities of biopsy tissue using culture-independent methods; (2) to culture the bacteria found in the tissues of patients with IBD but not in the controls; (3) to identify potential virulence factors associated with cultured bacteria. Methods: 84 biopsy specimens were collected from 15 controls, 13 patients with Crohn's disease (CD) and 19 patients with ulcerative colitis (UC) from a population-based case-control study. Ribosomal intergenic spacer analysis (RISA) was conducted to identify unique DNA bands in tissues from patients with CD and UC that did not appear in controls. Results: RISA followed by DNA sequencing identified unique bands in biopsy specimens from patients with IBD that were classified as Escherichia coli. Targeted culture showed a significantly (p,0.05) higher number of Enterobacteriaceae in specimens from patients with IBD. The B2+D phylogenetic group, serine protease autotransporters (SPATE) and adherence factors were more likely to be associated with tissues from patients with UC and CD than with controls. Conclusions: The abundance of Enterobacteriaceae is 3-4 logs higher in tissues of patients with IBD and the B2+D phylogenetic groups are more prevalent in patients with UC and CD. The B2+D phylogenetic groups are associated with SPATE and adherence factors and may have a significant role in disease aetiology.

We hypothesize that there is a recruitment phase in which potentially pathogenic bacteria colonize tissue, and once the inflammation sets in, a decline in diversity occurs that may be a byproduct of the inflammatory process. Furthermore, we suspect that a better knowledge of the microbial species in the noninflamed tissue, thus before inflammation sets in, holds the clues to the microbial pathogenesis of IBD.

The purpose of this study was to develop a simple procedure for cell lysis and DNA extraction for direct detection of Mycobacterium ulcerans in aquatic insects, gills and intestinal contents of fish, molluscs and human tissue samples using a nested PCR method specific for the insertion sequence IS2404. The simultaneous action of sodium N-lauroyl sarcosine, guanidinium isothiocyanate, chloroform and Tris-saturated phenol on mycobacteria, followed by a DNA purification method using mini-columns fitted with silica-cellulose membranes was successfully employed to extract DNA from cultured bacteria, environmental and human tissue samples. All specimens were collected from Buruli ulcer endemic regions. M. ulcerans DNA was detected in 11 of 57 aquatic insects, one of six molluscs and three of 15 fish, supporting the hypothesis that the fauna of major Buruli ulcer endemic foci in swampy terrain of tropical and subtropical regions can be a source of M. ulcerans infection.

Bacteria of the genus Staphylococcus are common pathogens responsible for a broad spectrum of human and animal infections and belong to the most important etiological factors causing food poisoning. Because of rapid increase in the prevalence of isolation of staphylococci resistant to many antibiotics, there is an urgent need for the development of new alternative chemotherapeutics. A number of studies have recently demonstrated the strong potential of peptidoglycan hydrolases (PHs) to control and treat infections caused by this group of bacteria. PHs cause rapid lysis and death of bacterial cells. The review concentrates on enzymes hydrolyzing peptidoglycan of staphylococci. Usually, they are characterized by high specificity to only Staphylococcus aureus cell wall components; however, some of them are also able to lyse cells of other staphylococci, e.g., Staphylococcus epidermidis-human pathogen of growing importance and also other groups of bacteria. Some PHs strengthen the bactericidal or bacteriostatic activity of common antibiotics, and as a result, they should be considered as component of combined therapy which could definitely reduced the development of bacterial resistance to both enzymes and antibiotics. The preliminary research revealed that most of these enzymes can be produced using heterologous, especially Escherichia coli expression systems; however, still much effort is required to develop more efficient and large-scale production technologies. This review discusses current state on knowledge with emphasis on the possibilities of application of PHs in the context of therapeutics for infections caused by staphylococci.

MLST analysis suggested that E. coli isolated from IBD patients did not evolve from a unique ancestral background. Together with the fimH sequence we conclude that AIEC represent a group of bacteria that have been able to take advantage of an "IBD microenvironment" and likely shares common genes with extraintestinal pathogens like uro-pathogenic CFT073 and avian-pathogenic O1:K1:H7 E. coli. Future research should focus on genes that are unique to AIEC.

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One of the most pressing problems of enterococci infections is occurring resistance to linezolid, which is an antibiotic used in the treatment of infections caused by vancomycin-resistant strains (VRE). The main objective of our research was to investigate the relationship of 19 linezolid-resistant E. faecium isolates from 18 patients hospitalized at Clinical Hospital in Gdansk (Poland). One of the LZD R EF was isolated in 2003 (K 2003 ), and another 18 were collected from 2013 to 2017. Genotyping with PCR MP method indicated 14 main unrelated genetic profiles and no association with K 2003 strain. Two isolates with the same genotype and genetically closely related two sub-types (2 isolates for each sub-type) were hospitalderived colonizations of patients. The other unrelated genotypes were discussed in the context of colonization, nosocomial infections, and commensal origin, taking into account prior exposure to linezolid. We determined the presence of a point mutation G2576T in six loci of 23S rDNA. There was also a significant correlation (p<0.0015) between the presence of MIC>32 value and the presence of G2576T point mutation on the sixth rrn. We also detected 5 virulence genes for all isolates: gelE, cylA, asa1, hyl, esp. Correlation (p�0.0001) was observed between the presence of gelE gene encoding gelatinase and two other genes: cylA and asa1 encoding cytolysin and collagen binding protein responsible for aggregation of bacterial cells, respectively. Significant correlation was also observed between asa1 and cfr genes encoding 23S rRNA rybonuclease responsible for resistance to PhLOPSA antibiotics (p = 0.0004). The multidimensional analysis has also shown the correlation between cfr gene and GI-tract (p = 0, 0491), which suggests horizontal gene transfer inside the gut microbiota and the risk of colonization with linezolid-resistant strains without previously being treated with the antibiotic. The patient could have been colonized with LZD R VREF strains which in the absence of competitive microbiota quickly settle in ecological niches favourable for them and pose a risk for the patient.