BACKGROUND: In the pre-vaccine era, invasive disease with Haemophilus influenzae, type b (Hib) commonly presented with osteoarticular involvement. Haemophilus influenzae, type a (Hia) sepsis is a rare but emerging problem in recent years. Here, we report a case of sepsis with concomitant osteoarthritis due to Hia that was the presenting infectious disease manifestation of isolated asplenia in a young child. This unique observation adds to our understanding of sepsis and asplenia in children.
METHODS: A five-year-old girl developed acute Hia bacteremia and sepsis. The patient developed arthritis shortly after onset of septic shock. Arthrocentesis was culture-negative, but given the difficulty differentiating between septic and reactive arthritis, prolonged antibiotic administration was provided for presumed osteoarticular infection, and the patient had an uneventful recovery. The finding of Howell-Jolly bodies on blood smear at the time of presentation prompted an evaluation that revealed isolated congenital asplenia. Evaluation for known genetic causes of asplenia was unrevealing. Investigation by the Minnesota Department of Health revealed an emergence of Hia infections over the past 5 years, particularly in children with an American Indian background.
CONCLUSIONS: Hia is an important pathogen in the differential diagnosis of invasive bacterial infections in children and shares overlap in clinical presentation and pathogenesis with Hib. Invasive Hia disease can be a presenting manifestation of asplenia in children. Hia is an emerging pathogen in American Indian children.

Hospital acquired infections (HAI) are principal threats to the patients of intensive care units. An increase in the antimicrobial resistance (AMR) observed in gram negative bacteria is a great challenge to deal with. HAI and AMR lead to prolonged hospitalization and additional doses of anti-microbial treatment affecting patient\'s fitness and finances. Present study was undertaken to determine the pathotypes, genetic diversity and the antimicrobial resistance of E.coli in isolates from the patients admitted to intensive care unit at a tertiary care hospital in Delhi, India.
E.coli isolates (N = 77) obtained from the blood culture of patients diagnosed with sepsis and the isolates (N = 71) from the stool culture of patients admitted in intensive care unit (ICU) but not diagnosed with sepsis were investigated for their pathotypes, adherence patterns and genetic diversity by Enterobacterial Repeated Intergenic Consensus-polymerase chain reaction (ERIC-PCR). A Kirby-Bauer Disc diffusion test and antimicrobial susceptibility assays were performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Extended-spectrum β-lactamase (ESBL) genes and sequence type 131 (ST131) clone were characterised genotypically by gene-specific PCRs.
Pathotypes analysis revealed 46 and 16% of the blood E.coli isolates were ETEC and EAEC respectively, in contrast to the fecal isolates wherein 22% of the isolates were ETEC and 28.5% were EAEC. EPEC, STEC and EIEC pathotypes were not detected in blood or fecal isolates. Of all the isolates studied, more than 90% of the blood and 70% of the fecal isolates were found to be resistant to cephalosporins. On the other hand, 68% of blood and 44% of the fecal isolates were found to be ESBL producers. Interestingly 83% of the blood isolates contained CTX-M15, whereas only 21% of them contained CTX-M9 genes. On the other hand CTX-M15 genes were found in 90% and CTX-M9 genes were found in 63% of the fecal isolates.
The antimicrobial resistant profile found in this study is alarming and poses a great threat to public health. Apparently an increased antimicrobial resistance to the extensively used cephalosporins is affecting an optimal drug therapy for patients. In addition, the presence of catheters, prolonged duration of stay in the hospital and poor hygienic conditions due to infrequent urination of the patient can lead to an additional vulnerability. Therefore continuous surveillance and rational use of antibiotics along with effective hygienic measures are urgently recommended in such settings.

BACKGROUND: Cases of macrolide-resistant Mycoplasma pneumoniae have increased rapidly since 2000, especially in Asia. Patients infected with macrolide-resistant M pneumoniae usually present with severe M pneumoniae pneumonia. The aim of this study was to identify indicators for whether children at an early stage of M pneumoniae infection develop mild or severe pneumonia.
METHODS: Herein, we retrospectively reviewed 2 pediatric cases caused by macrolide-resistant M pneumoniae, but with markedly different severity of pneumonia. First, we compared the clinical courses of the patients, then isolated the pathogens and tested their response to macrolides, then finally, carried out whole genome sequencing of these isolates. Despite the difference in clinical presentation of the infection, both isolates exhibited a high level of resistance to macrolide antibiotics. Analysis of clinical data showed that the erythrocyte sedimentation rate in blood samples of the patients in the early stages of disease varied greatly. Genome sequence analysis revealed single nucleotide polymorphisms mainly focused on adhesin P1, which is involved in the pathogenicity of M pneumoniae.
CONCLUSIONS: The differences of erythrocyte sedimentation rate in the early stage of M pneumoniae pneumonia and mutations in P1 protein may help us to distinguish between severe or mild disease after infection with macrolide-resistant M pneumoniae. These findings could lead to the development of screening assays that will allow us to distinguish severe or mild M pneumoniae pneumonia early.

BACKGROUND: Antibodies to citrullinated proteins (ACPA) occur years before RA diagnosis. Porphyromonas gingivalis expresses its own peptidylarginine deiminase (PPAD), and is a proposed aetiological factor for the ACPA response. Smoking is a risk factor for both ACPA-positive RA and periodontitis. We aimed to study the relation of these factors to the risk of RA in a prospective cohort.
METHODS: We performed a nested case-control study by identifying pre-RA cases in four populations from the European Prospective Investigation into Cancer and nutrition, matched with three controls. Data on smoking and other covariates were obtained from baseline questionnaires. Antibodies to CCP2 and citrullinated peptides from α-enolase, fibrinogen, vimentin and PPAD were measured. Antibodies to arginine gingipain (RgpB) were used as a marker for P.gingivalis infection and validated in a separate cohort of healthy controls and subjects with periodontitis.
RESULTS: We studied 103 pre-RA cases. RA development was associated with several ACPA specificities, but not with antibodies to citrullinated PPAD peptides. Antibody levels to RgpB and PPAD peptides were higher in smokers but were not associated with risk of RA or with pre-RA autoimmunity. Former but not current smoking was associated with antibodies to α-enolase (OR 4.06; 95 % CI 1.02, 16.2 versus 0.54; 0.09-3.73) and fibrinogen peptides (OR 4.24; 95 % CI 1.2-14.96 versus 0.58; 0.13-2.70), and later development of RA (OR 2.48; 95 % CI 1.27-4.84 versus 1.57; 0.85-2.93), independent of smoking intensity.
CONCLUSIONS: Smoking remains a risk factor for RA well before the clinical onset of disease. In this cohort, P.gingivalis is not associated with pre-RA autoimmunity or risk of RA in an early phase before disease-onset. Antibodies to PPAD peptides are not an early feature of ACPA ontogeny.

A library of 24 new mannose-centered tetragalactoclusters with four different linkers (di- and triethyleneglycol with phosphodiester or phosphorothioate linkages) and six different aromatic aglycons (O-phenyl, S-phenyl, O-benzyl, S-benzyl, O-biphenyl and O-naphthyl) was synthesized. Their interactions with LecA were evaluated on a DNA Directed Immobilization (DDI) based glycocluster array allowing the determination of their IC50 against lactose and the evaluation of their dissociation constant (Kd). Finally, the docking simulations confirm the experimental results and demonstrated that the better affinity of O-biphenyl- and O-naphthyl-galactoside is due to a double interaction between the aromatic ring and the histidine 50 and proline 51 of LecA.

Integrins require the divalent ions magnesium and manganese for ligand recognition. Here we mechanically enforced bond dissociation to explore the influence of these ions on the mechanical strength of the specific bond between α(7) β(1) integrin and its pathologically relevant ligand invasin. Upon addition of these cations to the measurement buffer, we observe a pronounced increase in the force necessary to separate integrin and invasin coated beads. Both ions were found to work synergistically. With free invasin in the measurement buffer we furthermore observe that competitive blocking of binding sites overrides the increase in binding strength of individual beads. We show that this is due to a very strong dependence of bond affinity on divalent ions. Our study illustrates the importance of divalent ions for the regulation of force transmission by integrin ligand bonds on the molecular level.

Invasive disease caused by meningococcal capsular groups A, C, W-135, and Y is now preventable by means of glycoconjugate vaccines that target their respective polysaccharide capsules. The capsule of group B meningococci (MenB) is poorly immunogenic and may induce autoimmunity. Vaccines based on the major immunodominant surface porin, PorA, are effective against clonal epidemics but, thus far, have a limited scope of coverage against the wider MenB population at large. In an alternative approach, the first-generation, investigational, recombinant MenB (rMenB) plus outer membrane vesicle (OMV) (rMenB-OMV) vaccine contains a number of relatively conserved surface proteins, fHBP, NHBA (previously GNA2132), and NadA, alongside PorA P1.4-containing OMVs from the New Zealand MeNZB vaccine. MenB currently accounts for approximately 90% of cases of meningococcal disease in England and Wales. To assess potential rMenB-OMV vaccine coverage of pathogenic MenB isolates within this region, all English and Welsh MenB case isolates from January 2008 (n = 87) were genetically characterized with respect to fHBP, NHBA, NadA, and PorA. Alleles for fHbp, nhba, and porA were identified in all of the isolates, of which 22% were also found to harbor nadA alleles. On the basis of genotypic data and predicted immunological cross-reactivity, the potential level of rMenB-OMV vaccine coverage in England and Wales ranges from 66% to 100%.

Atypical enteropathogenetic Escherichia coli (EPEC) strains are frequently detected in children with diarrhea but are also a common finding in healthy children. The aim of this study was to compare the phylogenetic ancestry and virulence characteristics of atypical (eae positive, stx and bfpA negative) EPEC strains from Norwegian children with (n = 37) or without (n = 19) diarrhea and to search for an association between phylogenetic ancestry and diarrhea. The strains were classified in phylogenetic groups by phylogenetic marker genes and in sequence types (STs) by multilocus sequence typing. Phylogenetic ancestry was compared to virulence characteristics based on DNA microarray analysis. Serotyping and pulsed-field gel electrophoresis (PFGE) were also performed. All four phylogenetic groups, 26 different STs, and 20 different clonal groups were represented among the 56 atypical EPEC strains. The strains were separated into three clusters by overall virulence gene profile; one large cluster with A, B1, and D strains and two clusters with group B2 strains. There was considerable heterogeneity in the PFGE profiles and serotypes, and almost half of the strains were O nontypeable. The efa1/lifA gene, previously shown to be statistically linked with diarrhea in this strain collection (J. E. Afset et al., J. Clin. Microbiol. 44:3703-3711, 2006), was present in 8 of 26 STs. The two phylogenetic groups B1 and D were weakly associated with diarrhea (P = 0.06 and P = 0.09, respectively). In contrast, group B2 was isolated most frequently from healthy controls (P = 0.05). In conclusion, the atypical EPEC strains were heterogeneous both phylogenetically and by virulence profile. Phylogenetic ancestry was less useful as a predictor of diarrhea than were specific virulence genes.

Two typical coliforms from an intestinal biopsy from an adult case of bloody diarrhoea carried genes encoding intimin-beta, stx(1) and ehxA, and produced verocytotoxin 1 and enterohaemolysin in culture. Both were biochemically typical Escherichia coli O5 :H(-), apart from producing urease. Such O5 isolates represent a human pathogenic E. coli lineage.

The Escherichia coli adhesin F17-G is a carbohydrate-binding protein that allows the bacterium to attach to the intestinal epithelium of young ruminants. The structure of the 17 kDa lectin domain of F17-G was determined using the anomalous dispersion signal of a selenium-containing analogue of the monosaccharide ligand N-acetyl-d-glucosamine in which the anomeric oxygen was replaced by an Se atom. A three-wavelength MAD data set yielded good experimental phases to 2.6 A resolution. The structure was refined to 1.75 A resolution and was used to solve the structures of the ligand-free protein and the F17-G-N-acetyl-d-glucosamine complex. This selenium-carbohydrate phasing method could be of general use for determining the structures of carbohydrate-binding proteins.