Invasive disease caused by the encapsulated bacteria Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae remains an important cause of morbidity and mortality worldwide, despite the introduction of successful conjugate polysaccharide vaccines that target disease-associated strains. In addition, resistance, or more accurately reduced susceptibility, to therapeutic antibiotics is spreading in populations of these organisms. There is therefore a continuing requirement for the surveillance of vaccine and non-vaccine antigens and antibiotic susceptibilities among isolates from invasive disease, which is only partially met by conventional methods. This need can be met with molecular and especially nucleotide sequence-based typing methods, which are fully developed in the case of N. meningitidis and which could be more widely deployed in clinical laboratories for S. pneumoniae and H. influenzae.

• MeSH
• epidemický výskyt choroby MeSH
• Haemophilus influenzae klasifikace   genetika   izolace a purifikace   MeSH
• hemofilové infekce epidemiologie   mikrobiologie   MeSH
• lidé MeSH
• meningokokové infekce epidemiologie   mikrobiologie   MeSH
• mikrobiální testy citlivosti MeSH
• molekulární epidemiologie metody   MeSH
• molekulární typizace metody   MeSH
• Neisseria meningitidis klasifikace   genetika   izolace a purifikace   MeSH
• pneumokokové infekce epidemiologie   mikrobiologie   MeSH
• Streptococcus pneumoniae klasifikace   genetika   izolace a purifikace   MeSH
• surveillance populace metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Neisseria meningitidis can utilize haem, haemoglobin and haemoglobin-haptoglobin complexes as sources of iron via two TonB-dependent phase variable haemoglobin receptors, HmbR and HpuAB. HmbR is over-represented in disease isolates, suggesting a link between haemoglobin acquisition and meningococcal disease. This study compared the distribution of HpuAB and phase variation (PV) status of both receptors in disease and carriage isolates. Meningococcal disease (n = 214) and carriage (n = 305) isolates representative of multiple clonal complexes (CCs) were investigated for the distribution, polyG tract lengths and ON/OFF status of both haemoglobin receptors, and for the deletion mechanism for HpuAB. Strains with both receptors or only hmbR were present at similar frequencies among meningococcal disease isolates as compared with carriage isolates. However, >90 % of isolates from the three CCs CC5, CC8 and CC11 with the highest disease to carriage ratios contained both receptors. Strains with an hpuAB-only phenotype were under-represented among disease isolates, suggesting selection against this receptor during systemic disease, possibly due to the receptor having a high level of immunogenicity or being inefficient in acquisition of iron during systemic spread. Absence of hpuAB resulted from either complete deletion or replacement by an insertion element. In an examination of PV status, one or both receptors were found in an ON state in 91 % of disease and 71 % of carriage isolates. We suggest that expression of a haemoglobin receptor, either HmbR or HpuAB, is of major importance for systemic spread of meningococci, and that the presence of both receptors contributes to virulence in some strains.

• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• meningokokové infekce mikrobiologie   MeSH
• molekulární sekvence - údaje MeSH
• Neisseria meningitidis genetika   izolace a purifikace   metabolismus   patogenita   MeSH
• přenašečství mikrobiologie   MeSH
• proteiny vnější bakteriální membrány genetika   metabolismus   MeSH
• receptory buněčného povrchu genetika   metabolismus   MeSH
• regulace genové exprese u bakterií MeSH
• virulence MeSH
• železo metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální proteiny MeSH
• HmbR protein, Neisseria meningitidis MeSH Prohlížeč
• HpuA protein, Neisseria MeSH Prohlížeč
• HpuB protein, Neisseria MeSH Prohlížeč
• proteiny vnější bakteriální membrány MeSH
• receptory buněčného povrchu MeSH
• železo MeSH