65 research outputs found
Ovine clone ST1464:A predominant genotype of Staphylococcus aureus subsp. anaerobius isolated from sheep in Sudan
Ovine clone ST1464:A predominant genotype of Staphylococcus aureus subsp. anaerobius isolated from sheep in Sudan
Multispacer Sequence Typing Relapsing Fever Borreliae in Africa
In Africa, relapsing fevers are caused by four cultured species: Borrelia crocidurae, Borrelia duttonii, Borrelia hispanica and Borrelia recurrentis. These borreliae are transmitted by the bite of Ornithodoros soft ticks except for B. recurrentis which is transmitted by louse Pediculus humanus. They cause potentially undifferentiated fever infection and co-infection with malaria could also occur. The exact prevalence of each Borrelia is unknown and overlaps between B. duttonii and B. crocidurae have been reported. The lack of tools for genotyping these borreliae limits knowledge concerning their epidemiology. We developed multispacer sequence typing (MST) and applied it to blood specimens infected by B. recurrentis (30 specimens), B. duttonii (18 specimens) and B. crocidurae (13 specimens), delineating these 60 strains and the 3 type strains into 13 species-specific spacer types. B. crocidurae strains were classified into 8 spacer types, B. duttonii into 3 spacer types and B. recurrentis into 2 spacer types. These findings provide the proof-of-concept that that MST is a reliable tool for identification and genotyping relapsing fever borreliae in Africa
Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry Identification of Mycobacteria in Routine Clinical Practice
Background: Non-tuberculous mycobacteria recovered from respiratory tract specimens are emerging confounder organisms for the laboratory diagnosis of tuberculosis worldwide. There is an urgent need for new techniques to rapidly identify mycobacteria isolated in clinical practice. Matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF MS) has previously been proven to effectively identify mycobacteria grown in high-concentration inocula from collections. However, a thorough evaluation of its use in routine laboratory practice has not been performed. Methodology: We set up an original protocol for the MALDI-TOF MS identification of heat-inactivated mycobacteria after dissociation in Tween-20, mechanical breaking of the cell wall and protein extraction with formic acid and acetonitrile. By applying this protocol to as few as 10 5 colony-forming units of reference isolates of Mycobacterium tuberculosis, Mycobacterium avium, and 20 other Mycobacterium species, we obtained species-specific mass spectra for the creation of a local database. Using this database, our protocol enabled the identification by MALDI-TOF MS of 87 M. tuberculosis, 25M. avium and 12 non-tuberculosis clinical isolates with identification scores $2 within 2.5 hours. Conclusions: Our data indicate that MALDI-TOF MS can be used as a first-line method for the routine identification of heatinactivated mycobacteria. MALDI-TOF MS is an attractive method for implementation in clinical microbiology laboratories i
Diversity of Staphylococcus aureus Isolates in European Wildlife
Staphylococcus aureus is a well-known colonizer and cause of infection among
animals and it has been described from numerous domestic and wild animal
species. The aim of the present study was to investigate the molecular
epidemiology of S. aureus in a convenience sample of European wildlife and to
review what previously has been observed in the subject field. 124 S. aureus
isolates were collected from wildlife in Germany, Austria and Sweden; they
were characterized by DNA microarray hybridization and, for isolates with
novel hybridization patterns, by multilocus sequence typing (MLST). The
isolates were assigned to 29 clonal complexes and singleton sequence types
(CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88,
CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425,
CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963)
were not described previously. Resistance rates in wildlife strains were
rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were
identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-
associated lineages CC479 and CC705 were not detected in wildlife in the
present study while, in contrast, a third common cattle lineage, CC97, was
found to be common among cervids. No Staphylococcus argenteus or
Staphylococcus schweitzeri-like isolates were found. Systematic studies are
required to monitor the possible transmission of human- and livestock-
associated S. aureus/MRSA to wildlife and vice versa as well as the possible
transmission, by unprotected contact to animals. The prevalence of S.
aureus/MRSA in wildlife as well as its population structures in different
wildlife host species warrants further investigation
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