Escherichia albertii is a recently recognized close relative of Escherichia coli. This emerging enteropathogen possesses a type III secretion system (T3SS) encoded by the locus of enterocyte effacement, similar to enteropathogenic and enterohemorrhagic E. coli (EPEC and EHEC). Shiga toxin-producing strains have also been identified. The genomic features of E. albertii, particularly differences from other Escherichia species, have not yet been well clarified. Here, we sequenced the genome of 29 E. albertii strains (3 complete and 26 draft sequences) isolated from multiple sources and performed intraspecies and intragenus genomic comparisons. The sizes of the E. albertii genomes range from 4.5 to 5.1 Mb, smaller than those of E. coli strains. Intraspecies genomic comparisons identified five phylogroups of E. albertii. Intragenus genomic comparison revealed that the possible core genome of E. albertii comprises 3,250 genes, whereas that of the genus Escherichia comprises 1,345 genes. Our analysis further revealed several unique or notable genetic features of E. albertii, including those responsible for known biochemical features and virulence factors and a possibly active second T3SS known as ETT2 (E. coli T3SS 2) that is inactivated in E. coli. Although this organism has been observed to be nonmotile in vitro, genes for flagellar biosynthesis are fully conserved; chemotaxis-related genes have been selectively deleted. Based on these results, we have developed a nested polymerase chain reaction system to directly detect E. albertii. Our data define the genomic features of E. albertii and provide a valuable basis for future studies of this important emerging enteropathogen.
We aimed to verify the effectiveness of real-time reverse transcription (rRT) polymerase chain reaction (PCR) for detecting cases of modified measles (M-Me) and for predicting super-spreader candidates through the experience of a measles outbreak dominated by M-Me in Yamagata, Japan, during March-April 2017. We applied rRT-PCR to specimens from 35 cases of M-Me, nine cases of typical measles (T-Me) and nine cases of prodromal stage of T-Me (P-Me). From rRT-PCR among the M-Me cases, peripheral blood mononuclear cells (PBMC) showed the highest positive rate (80.0%), followed by throat swab (48.6%), urine (33.3%) and serum (3.1%). The negative result of PBMC in M-Me cases was recovered by the result of a throat swab. In specimens of PBMC, throat swab and urine, M-Me group showed the significantly higher cycle of threshold (i.e., lower viral load) in the rRT-PCR than T-Me and P-Me groups, respectively. Furthermore, three super-spreaders in T-Me or P-Me showed an extremely low cycle of threshold in their throat swab specimens. rRT-PCR using PBMC and throat swab might be helpful for clinical management and measles control by certain detection of M-Me cases and by predicting super-spreading events resulting from measles cases with the high viral load.
MeV might exist in Japan. Accordingly, additional doses of measles vaccine may be needed especially for people aged 20-39 years to prevent measles importation and endemicity. Furthermore, to correctly and rapidly diagnose measles, especially to identify patients who could become primary cases, efforts to detect all measles cases using epidemiological and genetic approaches should be made in countries where measles elimination had been achieved.
ABSTRACT. A survey of antibodies to bovine immunodeficiency virus (BIV) known as bovine lentivirus and bovine leukemia virus (BLV) was conducted with samples from water buffalo and cattle populations in Pakistan. A total of 370 water buffaloes and 76 cattle were tested, and l0.3% and 15.8%, respectively, were found positive for anti-BIV p26 antibodies determined by Western blotting, while 0.8% of water buffaloes and no cattle were positive for anti-BLV antibodies determined by immunodiffusion test. BIV-seropositive water buffaloes and cattle were found to have BIV proviral DNA in the peripheral blood mononuclear cells determined by nested polymerase chain reaction. This is the first report of BIV infections in water buffaloes.-KEY WORDS: bovine immunodeficiency virus, bovine leukemia virus, water buffalo.
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