Closed Complete Annotated Genome Sequences of Five Haemophilus influenzae Biogroup aegyptius Strains

Abstract

Haemophilus influenzae biogroup aegyptius is a cause of conjunctivitis in children. Biogroup aegyptius strains also caused fatal outbreaks of invasive disease, known as Brazilian purpuric fever (BPF), in the 1980s. BPF is fatal if untreated. Here, we report the complete genome sequences of five strains of Haemophilus influenzae biogroup aegyptius.

Phasevarions in Haemophilus influenzae biogroup aegyptius control expression of multiple proteins

“…Interestingly, the modA7 allele in strain F3043 contained an AGCC (n) repeat tract, which is the first identified instance of the modA7 allele being potentially phase-variable; all previously identified modA7 alleles did not contain an AGCC (n) SSR tract, and were therefore unable to phase-vary ( 20 , 21 , 23 ). Strains F3047 ( 4 ), F3052 ( 28 ), NCTC8134, NCTC8502, and FDAARGOS_1478 (all unpublished) encoded the modA13 allele, which has previously been characterized in Neisseria gonorrhoeae ( 22 ).…”

“…To determine how prevalent the modA13 and modA16 variants are in H. influenzae biogroup aegyptius, we conducted an examination of all 10 H. influenzae biogroup aegyptius strains with a closed annotated genome available in NCBI GenBank (see Table 1 ). This determined that the modA16 allele was encoded in four of these strains, (strains F1946, F3028, F3037, and F3031) ( 2 , 28 ), all isolated in Brazil in the 1980s from patients presenting with BPF ( 2 ). The modA16 gene in all four of these strains contained variable numbers of AGCC (n) repeats, strongly indicative of phase-variable expression ( 28 ).…”

“…This determined that the modA16 allele was encoded in four of these strains, (strains F1946, F3028, F3037, and F3031) ( 2 , 28 ), all isolated in Brazil in the 1980s from patients presenting with BPF ( 2 ). The modA16 gene in all four of these strains contained variable numbers of AGCC (n) repeats, strongly indicative of phase-variable expression ( 28 ). The remaining six strains, either isolated from non-BPF patients or with no information on site of isolation, did not encode the modA16 allele.…”

“…Our examination of multiple H. influenzae biogroup aegyptius strains with closed annotated genomes ( 28 ) demonstrated the presence of two ModA alleles previously undescribed in Haemophilus spp. : the ModA13 allele, which has been shown to regulate a phasevarion in Neisseria gonorrhoeae ( 22 ), and the ModA16 allele, which has not been characterized in H. influenzae biogroup aegyptius , but had been observed before in NTHi isolates.…”

Copper Efflux System Required in Murine Lung Infection by Haemophilus influenzae Composed of a Canonical ATPase Gene and Tandem Chaperone Gene Copies

“…The cap locus (11 genes encoding capsule production) has 10 of these 11 genes duplicated in a cluster in H. influenzae type b ( 75 – 77 ), whereas in H. influenzae biogroup aegyptius , the entire hifABCDE locus encoding pilus production is duplicated ( 78 , 79 ). During the course of genome sequencing and assembly of several H. influenzae biogroup aegyptius strains, Phillips et al ( 80 ) noticed that the genome size of one of the strains sequenced was ~28 kb larger than the whole-genome shotgun contigs of the same strain deposited by another group. The authors concluded that the discovery of extra sequences was due to using a long-read sequencing platform instead of short-read sequencing.…”