Longitudinal analysis of the temporal evolution of Acinetobacter baumannii strains in Ohio, USA, by using rapid automated typing methods.

Genotyping methods are essential to understand the transmission dynamics of Acinetobacter baumannii. We examined the representative genotypes of A. baumannii at different time periods in select locations in Ohio, using two rapid automated typing methods: PCR coupled with electrospray ionization mass spectrometry (PCR/ESI-MS), a form of multi-locus sequence typing (MLST), and repetitive-sequence-based-PCR (rep-PCR).

Application of the Ibis-T5000 pan-Orthopoxvirus assay to quantitatively detect monkeypox viral loads in clinical specimens from macaques experimentally infected with aerosolized monkeypox virus.

Monkeypox virus (MPXV), a member of the family Poxviridae and genus Orthopoxvirus, causes a smallpox-like disease in humans. A previously described pan-Orthopoxvirus assay, based on a broad-range polymerase chain reaction (PCR) coupled with electrospray ionization mass spectrometry (PCR/ESI-MS), was evaluated for its ability to detect MPXV from spiked human and aerosol-infected cynomolgous macaque (Macaca fascicularis) samples. Detection of MPXV DNA from macaque tissue, blood, and spiked human blood by the PCR/ESI-MS pan-Orthopoxvirus assay was comparable, albeit at slightly higher levels, to the current gold standard method of real-time PCR with the pan-Orthopoxvirus assay and had a limit of detection of 200 plaque-forming units.

Rapid and high-throughput pan-Orthopoxvirus detection and identification using PCR and mass spectrometry.

The genus Orthopoxvirus contains several species of related viruses, including the causative agent of smallpox (Variola virus). In addition to smallpox, several other members of the genus are capable of causing human infection, including monkeypox, cowpox, and other zoonotic rodent-borne poxviruses. Therefore, a single assay that can accurately identify all orthopoxviruses could provide a valuable tool for rapid broad orthopovirus identification.

Genotypic evolution of Acinetobacter baumannii strains in an outbreak associated with war trauma.

The Walter Reed Army Medical Center has experienced an influx of traumatically injured patients either infected or colonized with Acinetobacter baumannii. Using multilocus polymerase chain reaction (PCR) and mass spectrometry to genotype isolates, we found an atypical and evolving strain distribution, distinct from those found at nonmilitary hospitals in the United States.

Direct broad-range detection of alphaviruses in mosquito extracts.

Members of the genus Alphavirus are a diverse group of principally mosquito-borne RNA viruses. There are at least 29 species and many more subtypes of alphaviruses and some are considered potential bioweapons. We have developed a multi-locus RT-PCR followed by electrospray ionization mass spectrometry (RT-PCR/ESI-MS) assay that uses the amplicon base compositions to detect and identify alphaviruses.

A new method for accurate assessment of DNA quality after bisulfite treatment.

The covalent addition of methylgroups to cytosine has become the most intensively researched epigenetic DNA marker. The vast majority of technologies used for DNA methylation analysis rely on a chemical reaction, the so-called 'bisulfite treatment', which introduces methylation-dependent sequence changes through selective chemical conversion of non-methylated cytosine to uracil. After treatment, all non-methylated cytosine bases are converted to uracil but all methylated cytosine bases remain cytosine.