Background Escherichia coli strains adhere to the normally sterile human uroepithelium using type 1 pili, that are long, hairy surface organelles exposing a mannose-binding FimH adhesin at the tip. A small percentage of adhered bacteria can successfully invade bladder cells, presumably via pathways mediated by the high-mannosylated uroplakin-Ia and α3β1 integrins found throughout the uroepithelium. Invaded bacteria replicate and mature into dense, biofilm-like inclusions in preparation of fluxing and of infection of neighbouring cells, being the major cause of the troublesome recurrent urinary tract infections.Methodology/Principal FindingsWe demonstrate that α-d-mannose based inhibitors of FimH not only block bacterial adhesion on uroepithelial cells but also antagonize invasion and biofilm formation. Heptyl α-d-mannose prevents binding of type 1-piliated E. coli to the human bladder cell line 5637 and reduces both adhesion and invasion of the UTI89 cystitis isolate instilled in mouse bladder via catheterization. Heptyl α-d-mannose also specifically inhibited biofilm formation at micromolar concentrations. The structural basis of the great inhibitory potential of alkyl and aryl α-d-mannosides was elucidated in the crystal structure of the FimH receptor-binding domain in complex with oligomannose-3. FimH interacts with Manα1,3Manβ1,4GlcNAcβ1,4GlcNAc in an extended binding site. The interactions along the α1,3 glycosidic bond and the first β1,4 linkage to the chitobiose unit are conserved with those of FimH with butyl α-d-mannose. The strong stacking of the central mannose with the aromatic ring of Tyr48 is congruent with the high affinity found for synthetic inhibitors in which this mannose is substituted for by an aromatic group.Conclusions/SignificanceThe potential of ligand-based design of antagonists of urinary tract infections is ruled by the structural mimicry of natural epitopes and extends into blocking of bacterial invasion, intracellular growth and capacity to fluxing and of recurrence of the infection.

Association between nasopharyngeal load of Streptococcus pneumoniae, viral co-infection and radiologically confirmed pneumonia in Vietnamese children.

Hospitalized Vietnamese children with acute respiratory infection (ARI) were investigated for 13 viral pathogens using multiplex-polymerase chain reaction. We enrolled 958 children of whom 659(69%) had documented viral infection: rhinovirus (28%), respiratory syncytial virus (23%), influenza virus (15%), adenovirus (5%), human metapneumo virus (4.5%), parainfluenza virus (5%) and bocavirus (2%). These Vietnamese children had a range of respiratory viruses which underscores the need for enhanced ARI surveillance in tropical developing countries. Positive templates were used in each assay for quality control. RESULTSDuring the 14-months study period, a total of 1,014 pediatric patients from the catchment area were admitted to KHGH, of which 958 (95%) were enrolled in the study.Males comprised 58% of patients and 94% of the patients were less than 5 years old (median age: 1.4 years). The results showed that one or more respiratory viruses were found in 69% of patients: 11% had dual and 1.4% had triple infection. Eighty six percent of the viral ARI patients were less than 3 years old (detail information of age breakdown is shown in supplementary table 2, online only).Major viruses detected were rhinovirus (28%), RSV (23%) and influenza A (15%). This was followed by adenovirus (5%), hMPV (5%), PIV3 (4%) and bocavirus (2%). Other viruses (PIV1, PIV2 and influenza B) were detected in a small proportion (1.5%) of ARI patients. Across age, sex, and case categories, there were no significant differences between proportion of virus positive and negative patients.The pattern of virus detection did not differ between URTI and LRTI patients. A total of 268 radiologically-confirmed pneumonia (RCP) patients and 195 bronchiolitis 7 patients were identified. PIV3 detection was significantly associated with hospitalized LRTI (p=0.016) and bronchiolitis (p=<0.001). Similar to previous reports, we found that RSV infection was significantly associated with bronchiolitis (p=0.002) (6). We also found that a significantly higher proportion of patients (n=119)

Background: Guinea pig serum and liver contain an enzyme with L-asparaginase activity. Results: H0W0T5_CAVPO (gpASNase1) displays a low micromolar K m with Asn. Structures of apo and ASP complex are presented. Conclusion: gpASNase1is the likely identity of a guinea pig L-asparaginase endowed with anticancer properties. Significance: The high sequence identity to the human enzymes and its lack of L-glutaminase activity make gpASNase1 a potential replacement for the bacterial enzymes.

Four children in three unrelated families (one consanguineous) presented with lethargy, hyperlactatemia, and hyperammonemia of unexplained origin during the neonatal period and early childhood. We identified and validated three different CA5A alterations, including a homozygous missense mutation (c.697T>C) in two siblings, a homozygous splice site mutation (c.555G>A) leading to skipping of exon 4, and a homozygous 4 kb deletion of exon 6. The deleterious nature of the homozygous mutation c.697T>C (p.Ser233Pro) was demonstrated by reduced enzymatic activity and increased temperature sensitivity. Carbonic anhydrase VA (CA-VA) was absent in liver in the child with the homozygous exon 6 deletion. The metabolite profiles in the affected individuals fit CA-VA deficiency, showing evidence of impaired provision of bicarbonate to the four enzymes that participate in key pathways in intermediary metabolism: carbamoylphosphate synthetase 1 (urea cycle), pyruvate carboxylase (anaplerosis, gluconeogenesis), propionyl-CoA carboxylase, and 3-methylcrotonyl-CoA carboxylase (branched chain amino acids catabolism). In the three children who were administered carglumic acid, hyperammonemia resolved. CA-VA deficiency should therefore be added to urea cycle defects, organic acidurias, and pyruvate carboxylase deficiency as a treatable condition in the differential diagnosis of hyperammonemia in the neonate and young child.