Clinical and microbiological characteristics of <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> isolates causing community-acquired urinary tract infections

Background  

Klebsiella pneumoniae is the second most common species causing urinary tract infections (UTI). However, the host factors and virulence genes of K. pneumoniae related to UTI are poorly understood. The aim of this study was to analyze the capsular phenotype and virulence genes of K. pneumoniae isolates and host factors potentially relevant to community-acquired UTI.     

Antimicrobial activity of innate immune molecules against <Emphasis Type="Italic">Streptococcus pneumoniae,Moraxella catarrhalis</Emphasis> and nontypeable <Emphasis Type="Italic">Haemophilus influenzae</Emphasis>

Background  

Despite its direct connection to the nasopharynx which harbors otitis media pathogens as part of its normal flora, the middle ear cavity is kept free of these bacteria by as yet unknown mechanisms. Respiratory mucosal epithelia, including those of the middle ear and eustachian tube, secrete antimicrobial effectors including lysozyme, lactoferrin and β defensins-1 and -2. To elucidate the role of these innate immune molecules in the normal defense and maintenance of sterility of respiratory mucosa such as that of the middle ear, we assessed their effect on the respiratory pathogens nontypeable Haemophilus influenzae (NTHi) 12, Moraxella catarrhalis 035E, and Streptococcus pneumoniae 3, and 6B.     

Pneumonia Due to Drug-Resistant <Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis>

Pneumonia is a major infectious disease associated with significant morbidity and mortality, with Streptococcus pneumoniae the predominant pathogen in community-acquired cases, accounting for 20% to 50% of bacterial cases. Although pneumococcal resistance to β-lactams is now common worldwide, high-dose parental penicillin G, many other parental β-lactams and some oral β-lactams continue to be efficacious. The new Clinical and Laboratory Standards Institute susceptibility breakpoints for parental penicillin G for nonmeningeal infections (≤2 μg/mL, susceptible; 4 μg/mL, intermediate; ≥8 μg/mL, resistant) introduced in 2008 facilitate appropriate reporting and use of penicillin G. Pneumococcal vaccine usage in children from 2000 has led to significant decreases in morbidity and mortality due to S. pneumoniae in all age groups, and the increase in resistant serotypes, such as 19A, appears to be decreasing following the introduction of an expanded valence vaccine in 2010. Judicious use of antimicrobial agents is the best long-term approach in order to reduce S. pneumoniae resistance.     

High carriage rate of high-level penicillin-resistant <Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis>in a Taiwan kindergarten associated with a case of pneumococcal meningitis

Background  

The Taiwan^19F-14 Streptococcus pneumoniae clone and its variants are being found with increasing frequency in the Asia-Pacific region. A 5-year old child with S. pneumoniae meningitis caused by a high-level penicillin resistant strain (MIC = 4 μg/ml) was admitted to a hospital in southern Taiwan. We carried out a study to determine the potential source of this strain.     

Smoking,season, and detection of <Emphasis Type="Italic">chlamydia pneumoniae</Emphasis>DNA in clinically stable COPD patients

Background  

The prevalence and role of Chlamydia pneumoniae in chronic obstructive pulmonary disease (COPD) remain unclear.     

Rapamycin can Inhibit the Development of <Emphasis Type="Italic">Chlamydia pneumoniae</Emphasis>, which Might Partly Contribute to the Prevention of In-stent Restenosis

Background  

Rapamycin, an immunosuppressive and antiproliferative drug, is used to prevent neointima formation to reduce the risk of in-stent restenosis with rapamycin eluting-stents. Chronic infection of Chlamydia pneumoniae has been associated with cardiovascular diseases, and could play an important role in the mechanism of restenosis. We examined the effect of rapamycin on the growth of C. pneumoniae in cell cultures.     

Bacteremic community-acquired pneumonia due to <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis>: Clinical and microbiological characteristics in Taiwan, 2001-2008

Background  

Klebsiella pneumoniae is the major cause of community-acquired pyogenic infections in Taiwan. This retrospective study evaluated the clinical and microbiological characteristics of bacteremic community-acquired pneumonia due to K. pneumoniae in Taiwanese adults.     

<Emphasis Type="Italic">Chlamydia pneumoniae</Emphasis> Infections in Asthma

Chlamydia pneumoniae is an intracellular pathogen that has been suggested to play a role in the pathology of asthma. However, so far none of the studies have provided clear evidence for a causative role of C. pneumoniae infections in asthma, although there is little doubt that chronic C. pneumoniae infection does aggravate asthma and should be treated.The diagnosis of C. pneumoniae infection is still a matter of concern for it is dependent on trained skilled personnel and can vary significantly between different diagnostic laboratories. This fact is also one of the major problems encountered when comparing epidemiological studies investigating the possible role of C. pneumoniae infections and their impact on the pathogenesis of other diseases.With regard to therapy, long-term treatment with macrolides is the best available method to eradicate C. pneumoniae. Successful therapy for C. pneumoniae, however, can also be complicated by the high possibility of de novo infection as epidemiological studies have shown that the prevalence of antibodies to C. pneumoniae increases with age in all populations studied. In the northern hemisphere the prevalence of C. pneumoniae is also affected by seasonal conditions. It is too early to draw any conclusions from the equatorial belt countries. The available data on C. pneumoniae in tropical countries indicate a much faster infection rate during early adulthood with 100% serological prevalence at an age greater than 25 years. This data, if confirmed, would argue against C. pneumoniae causing asthma since the asthma prevalence in those countries does not increase in a parallel pattern.An alternative interpretation of most studies could be that the increased rate of C. pneumoniae infections in patients with asthma results from a modified susceptibility towards the microorganism, due to yet unknown changes of the host cell’s physiology. It should be kept in mind that increased prevalence of C. pneumoniae infection is not restricted to asthma.Further studies are needed to understand the role of C. pneumoniae, especially of chronic infection, in the pathogenesis of inflammatory diseases with a specific focus on the effect that the microorganism triggers in the infected host cell. Only when we understand what C. pneumoniae does to its host cell will we be able to judge its impact on the overall status of an affected patient, and this knowledge will help us to develop a successful therapy.     

Immune ageing and susceptibility to <Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis>

Streptococcus pneumoniae is a complex Gram-positive bacterium comprising over 90 different serotypes and is a major cause of pneumonia. Susceptibility to S. pneumoniae is remarkably age-related being greatest in children under 5 years old and adults over 65. Whilst the immaturity of the immune system is largely responsible for poor immunity in the former, the underlying causes of susceptibility in older adults is complex. Immunity to S. pneumoniae is mediated predominantly through the inflammatory response in the nasopharyngeal mucosa recruiting phagocytes (neutrophils and monocyte/macrophages) which recognise the pathogen via TLR2 and ingest and kill the bacteria, with the induction of Th17 cells being required to maintain neutrophil recruitment and ensure clearance of the infection. In this review we discuss the impact of ageing upon these aspects of immunity to S. pneumoniae, as well as age-related changes to the serotypes present in the adult nasopharyngeal tract which could further influence susceptibility to infection.     

The dynamics of nasopharyngeal <Emphasis Type="Italic">streptococcus</Emphasis> pneumoniae carriage among rural Gambian mother-infant pairs

Background  

Streptococcus pneumoniae is an important cause of community acquired pneumonia, sepsis, meningitis and otitis media globally and has been incriminated as a major cause of serious childhood bacterial infections in The Gambia. Better understanding of the dynamics of transmission and carriage will inform control strategies.     

Drug-resistant <Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis> in community-acquired pneumonia

The emergence of Streptococcus pneumoniae isolates resistant to not only penicillin, but to other antipneumococcal agents as well, has major public health implications. Drug-resistant S. pneumoniae are distributed worldwide, and resistance has become increasingly prevalent in the United States within the past decade. The relevance of resistance, particularly to the β-lactams, to treatment outcome has been subject to debate. Pneumonia due to intermediate-level-resistant penicillinresistant isolates of S. pneumoniae appears to be adequately treated by β-lactam agents. Interpretation of resistance reports, which may be based on achievable cerebrospinal fluid levels of drug, may depend on the clinical setting, and efforts are underway to adjust breakpoints so that reports are more easily applicable to clinical practice. Infectious Diseases Society of America and American Thoracic Society guidelines, as well as others, for community-acquired pneumonia have addressed the impact of drug-resistant S. pneumoniae on antimicrobial selection.     

Serotype-specific mortality from invasive <Emphasis Type="Italic">Streptococcus pneumoniae</Emphasis>disease revisited

Background

Invasive infection with Streptococcus pneumoniae (pneumococci) causes significant morbidity and mortality. Case series and experimental data have shown that the capsular serotype is involved in the pathogenesis and a determinant of disease outcome.

Methods

Retrospective review of 464 cases of invasive disease among adults diagnosed between 1990 and 2001. Multivariate Cox proportional hazard analysis.

Results

After adjustment for other markers of disease severity, we found that infection with serotype 3 was associated with an increased relative risk (RR) of death of 2.54 (95% confidence interval (CI): 1.22–5.27), whereas infection with serotype 1 was associated with a decreased risk of death (RR 0.23 (95% CI, 0.06–0.97)). Additionally, older age, relative leucopenia and relative hypothermia were independent predictors of mortality.

Conclusion

Our study shows that capsular serotypes independently influenced the outcome from invasive pneumococcal disease. The limitations of the current polysaccharide pneumococcal vaccine warrant the development of alternative vaccines. We suggest that the virulence of pneumococcal serotypes should be considered in the design of novel vaccines.

     

Diagnostic relevance of simultaneous testing for <Emphasis Type="Italic">Chlamydia trachomatis</Emphasis> and <Emphasis Type="Italic">Neisseria gonorrhoeae</Emphasis>

Background  

The prevalence of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infection in a Swiss cohort among individuals consulting for screening or symptomatic reasons is not very well known.     

<Emphasis Type="Italic">ARNTL2</Emphasis> and <Emphasis Type="Italic">SERPINE1</Emphasis>: potential biomarkers for tumor aggressiveness in colorectal cancer

Purpose  

Cathepsin and plasmin may favor cancer cell invasion degrading extracellular matrix. Plasmin formation from plasminogen is regulated by plasminogen activator inhibitor type-1 (PAI-1). ARNTL2 activates the promoters of the PAI-1 gene, officially called SERPINE1, driving the circadian variation in circulating PAI-1 levels.     

Gene Transfer of <Emphasis Type="Italic">c</Emphasis>-<Emphasis Type="Italic">met</Emphasis> Confers Protection Against <Emphasis Type="SmallCaps">d</Emphasis>-Galactosamine/Lipopolysaccharide-Induced Acute Liver Failure

Background  

Acute liver failure (ALF) is characterized by impaired regeneration of hepatocytes, partially resulting from the defective signaling between elevated levels of hepatocyte growth factor (HGF) and the downregulation of its receptor, c-met.     

Alterations of tumor suppressor gene <Emphasis Type="Italic">p16</Emphasis><Superscript><Emphasis Type="Italic">INK4a</Emphasis></Superscript>in pancreatic ductal carcinoma

Background  

Cell cycle inhibitor and tumor suppressor gene p16 / MTS-1 has been reported to be altered in a variety of human tumors. The purpose of the study was to evaluate primary pancreatic ductal adenocarcinomas for potentially inactivating p16 alterations.     

Predominant <Emphasis Type="Italic">porB1A</Emphasis> and <Emphasis Type="Italic">porB1B</Emphasis> genotypes and correlation of gene mutations with drug resistance in <Emphasis Type="Italic">Neisseria gonorrhoeae</Emphasis> isolates in Eastern China

Background  

Variations of porB1A and porB1B genes and their serotypes exist in Neisseria gonorrhoeae isolates from different geographical areas, and some site mutations in the porB1B gene correlate with drug resistance.     

Evaluation and optimization of a commercial enzyme linked immunosorbent assay for detection of <Emphasis Type="Italic">Chlamydophila pneumoniae</Emphasis>IgA antibodies

Background  

Serologic diagnosis of Chlamydophila pneumoniae (Cpn) infection routinely involves assays for the presence of IgG and IgM antibodies to Cpn. Although IgA antibodies to Cpn have been found to be of interest in the diagnosis of chronic infections, their significance in serological diagnosis remains unclear. The microimmunofluorescence (MIF) test is the current method for the measurement of Cpn antibodies. While commercial enzyme linked immunosorbent assays (ELISA) have been developed, they have not been fully validated. We therefore evaluated and optimized a commercial ELISA kit, the SeroCP IgA test, for the detection of Cpn IgA antibodies.     

Risks Factors for Infections with Extended-Spectrum Beta-Lactamase-Producing <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> at a Tertiary Care University Hospital in Switzerland

Background:   

There are considerable geographical differencesin the occurrence of extended-spectrum beta-lactamase(ESBL)-producing bacteria, both in the community and in thehospital setting. Our aim was to assess risk factors forbloodstream, urinary tract, and vascular catheter-associatedinfections with ESBL-producing Escherichia coli and Klebsiellapneumoniae at a tertiary care hospital in a low-prevalencecountry.     

Common variants in <Emphasis Type="Italic">CNDP1</Emphasis> and <Emphasis Type="Italic">CNDP2</Emphasis>, and risk of nephropathy in type 2 diabetes

Aims/hypothesis  

Several genome-wide linkage studies have shown an association between diabetic nephropathy and a locus on chromosome 18q harbouring two carnosinase genes, CNDP1 and CNDP2. Carnosinase degrades carnosine (β-alanyl-l-histidine), which has been ascribed a renal protective effect as a scavenger of reactive oxygen species. We investigated the putative associations of genetic variants in CNDP1 and CNDP2 with diabetic nephropathy (defined either as micro- or macroalbuminuria) and estimated GFR in type 2 diabetic patients from Sweden.