Staphylococcus epidermidis CSF41498 is amenable to genetic manipulation and has been used to study mechanisms of biofilm formation. We report here the whole-genome sequence of this strain, which ...contains 2,427 protein-coding genes and 82 RNAs within its 2,481,008-bp-long genome, as well as three plasmids.
Non-sorbitol-fermenting, beta-glucuronidase-negative Escherichia coli O157:H7 strains are regarded as a clone complex, and populations from different geographical locations are believed to share a ...recent common ancestor. Despite their relatedness, high-resolution genotyping methods can detect significant genome variation among different populations. Phylogenetic analysis of high-resolution genotyping data from these strains has shown that subpopulations from geographically unlinked continents can be divided into two primary phylogenetic lineages, termed lineage I and lineage II, and limited studies of the distribution of these lineages suggest there could be differences in their propensity to cause disease in humans or to be transmitted to humans. Because the genotyping methods necessary to discriminate the two lineages are tedious and subjective, these methods are not particularly suited for studying the large sets of strains that are required to systematically evaluate the ecology and transmission characteristics of these lineages. To overcome this limitation, we have developed a lineage-specific polymorphism assay (LSPA) that can readily distinguish between the lineage I and lineage II subpopulations. In the studies reported here, we describe the development of a six-marker test (LSPA-6) and its validation in a side-by-side comparison with octamer-based genome scanning. Analysis of over 1,400 O157:H7 strains with the LSPA-6 demonstrated that five genotypes comprise over 91% of the strains, suggesting that these subpopulations may be widespread.
To determine whether a relationship exists between biofilm formation and hemagglutination in Staphylococcus epidermidis, 20 skin isolates and 19 prosthetic valve endocarditis isolates were ...characterized for biofilm formation, hemagglutination, and the presence of a 357-bp polymerase chain reaction product within icaA. A strong association existed between biofilm formation, which has been linked to strains that produce polysaccharide intercellular adhesin (PIA), and hemagglutination. Strains that produced biofilm were significantly (P < .001 more likely to mediate hemagglutination (16 biofilm-positive/hemagglutination-positive strains and 19 biofilm-negative/hemagglutination-negative strains) within the 39 clinical strains tested. In addition, Staphylococcus carnosus TM300, a biofilm-negative, hemagglutination-negative strain, carrying the ica operon-containing plasmid pCN27, produced significant biofilm on glass and mediated hemagglutination (⩾1/128). It was concluded that production of PIA and hemagglutination are strongly associated and that PIA, at least in part, mediates hemagglutination in S. epidermidis.
Transverse sections of otoliths from Atlantic cod Gadus morhua from the Baltic Sea revealed narrow growth increments. The widths of these increments corresponded to daily increments from fish with ...known otolith growth rates and were therefore assumed to be daily increments. They exhibited a distinct pattern with increasing distance from the primary primordium. A series of zones with clearly distinguishable increments, first with increasing then with decreasing widths in a dome‐shaped pattern, were separated by zones where no regular increment structure was visible. Increment width seemed to be tightly coupled to the annual cycle in environmental temperature at a depth of 30–60 m, where G. morhua predominantly reside. Between 135 and 200 increments occurred within the different zones, with a non‐significant trend towards lower increment numbers and widths with distance from the primary primordium of the otolith. Increment formation apparently ceased at temperatures < 5–6° C, but growth during the cold months corresponded closely with estimated growth rates. The increment patterns seemed to reflect annual cycles in environmental temperature, and the count of the increment cycles may thus be a promising tool for the determination of the true age of Baltic G. morhua.
Extended-spectrum cephalosporins (ESC) are an important drug class for treating severe Salmonella infections. We screened the human collection from the National Antimicrobial Resistance Monitoring ...System 2000 for ESC resistance mechanisms. Of non-Typhi Salmonella tested, 3.2% (44/1,378) contained blaCMY genes. Novel findings included blaCMY-positive Escherichia coli O157:H7 and a blaSHV-positive Salmonella isolate. CMY-positive isolates showed a ceftriaxone MIC > or =2 microg/mL.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Over recent decades, the Arctic region has been subjected to rapid climate change stemming from global warming. The advance of Atlantic waters to high latitudes is notable. The increased abundance of ...fish, such as cod (Gadus morhua) and haddock (Melanogrammus aeglefinus), has been reported near the western coast of Spitsbergen and entering fjords together with Atlantic waters. This study used multifrequency acoustics to measure fish distribution and abundance in 2013–2014 in two Arctic fjords, the colder Hornsund, which is typically of Arctic character, and the warmer Kongsfjorden, which is more of Atlantic character. The study revealed a bimodal fish size distribution with larger fish in the deep parts of fjords, and smaller fish distributed in more shallow waters. An evident increase in the abundance of large fish, most probably Atlantic cod, was observed in Hornsund and especially in Kongsfjorden in 2014 in comparison to 2013. The intense inflow of Atlantic water on the shelf in 2014 is suggested as the explanation for this phenomenon.
Rapid methods are needed for public health and military applications to specifically identify Francisella tularensis, the causative agent of tularemia in humans. A comparative analysis of the ...capabilities of multiple technologies was performed using a well-defined set of organisms to determine which approach would provide the most information in the shortest time. High-resolution molecular techniques, including pulsed-field gel electrophoresis, amplified fragment length polymorphism, and ribotyping, provided subspecies level identification within approximately 24 hours after obtaining an isolate, whereas multilocus variable number tandem repeat analysis with 8 or 25 targets provided strain level discrimination within about 12 hours. In contrast, Raman spectroscopy provided species level identification in 10 minutes but could not differentiate between subspecies tularensis and holarctica.
1 Department of Internal Medicine and Infectious Disease, University of Nebraska Medical Center, Omaha, USA
2 Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, ...USA
Correspondence Ziba Jalali zjalali{at}unmc.edu
Received 20 January 2008
Accepted 9 April 2008
Daptomycin is a novel bactericidal agent active against Gram-positive pathogens including meticillin-resistant Staphylococcus aureus (MRSA). Our case is unique in the description of an MRSA USA 300 isolate that developed decreased susceptibility to daptomycin during daptomycin and vancomycin therapy. Directed sequencing detected a previously reported mutation in mprF , resulting in a T345A substitution, associated with non-susceptibility to daptomycin.
Abbreviations: MRSA, meticillin-resistant Staphylococcus aureus .
A rat central venous catheter (CVC) infection model was used to assess the activity of LY333328 against vancomycin-resistant Enterococcus faecium (VRE). Via the CVC, animals were challenged with 106 ...cfu of Enterococcus faecium with the VanA phenotype. Eight rats received a single dose of LY333328 and eight rats received saline. Seventy-five per cent of control animals had peripheral bacteraemia and 87.5% had VRE recovered from explanted CVCs at the time they were killed, as compared with 0 and 12.5%, respectively, of the LY333328-treated animals (P < 0.01). All animals in the control group had evidence of metastatic disease compared with none of the treated group (P < 0.01). LY333328 was effective against the strain of VRE tested in this model.
Limited information exists regarding Klebsiella pneumoniae's production of an extended-spectrum β-lactamase (KP-ESBL) in pediatric patients, particularly solid-organ transplant recipients. This study ...characterized the microbiological, epidemiological, and clinical features of a KP-ESBL outbreak in children receiving a liver transplant, an intestinal transplant, or both. All children found to have microbiologically confirmed K. pneumoniae during a 21-month period were reviewed. ESBL production was defined by double-disk diffusion, and 6 distinct pulsed-field gel electrophoresis patterns were identified. Fifty-six percent of the transplant patients we studied developed KP-ESBL, representing 87% of all microbiologically confirmed cases at our institution. As compared with 16 control transplant patients who were negative for KP-ESBL, the 20 transplant patients who acquired KP-ESBL were younger (aged ⩽5 years; 80.0% vs. 43.8%, P = .038) and experienced placement of ⩾3 central venous catheters before recovery of the first K. pneumoniae isolate (73.7% vs. 18.8%, P = .002). This study suggests that children who receive liver or intestinal transplants are at high risk for KP-ESBL acquisition.
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