Tài liệu Báo cáo Y học: Structure of the O-polysaccharide and classification of Proteus mirabilis

Structure of the O-polysaccharide and classification

of Proteus mirabilis strain G1 in Proteus serogroup O3

Zygmunt Sidorczyk1

, Krystyna Zych1

, Filip V. Toukach2

, Nikolay P. Arbatsky2

, Agnieszka Zablotni1

,

Alexander S. Shashkov2 and Yuriy A. Knirel2

1

Department of General Microbiology, Institute of Microbiology and Immunology, University of Lodz, Poland; 2

N.D. Zelinsky

Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation

The O-chain polysaccharide of the lipopolysaccharide (LPS)

of a previously nonclassified strain of Proteus mirabilis

termed G1 was studied by sugar analysis and 1

H and 13C

NMR spectroscopy, including 2D COSY, TOCSY, rota￾ting-frame NOE (ROESY), H-detected 1

H,13C HMQC, and

heteronuclear multiple-bond correlation (HMBC) experi￾ments. The following structure of the polysaccharide was

established:

where D-GalA6(L-Lys) stands for Na

-(D-galacturonoyl)-

L-lysine. The structure of the O-polysaccharide of

P. mirabilis G1 is similar, but not identical, to that of

P. mirabilis S1959 and OXK belonging to serogroup O3.

Immunochemical studies with P. mirabilis G1 and S1959

anti-(O-polysaccharide) sera revealed close LPS-based

serological relatedness of P. mirabilis G1 and S1959, and

therefore it was suggested to classify P. mirabilis G1 in

serogroup O3 as a subgroup. P. mirabilis G1 and S1959

anti-(O-polysaccharide) sera also cross-reacted with LPS

of P. mirabilis strains from two other serogroups contain￾ing D-GalA6(L-Lys) in the O-polysaccharide or in the core

region.

Keywords: Proteus mirabilis; O-polysaccharide; lipopoly￾saccharide; Na

-(D-galacturonoyl)-L-lysine; serogroup.

Much has been written about the taxonomy of Proteussince

the original publication by Hauser in 1885 who established

the genus [1]. Currently, the genus Proteus consists of

five named species (P. mirabilis, P. penneri, P. vulgaris,

P. myxofaciens and P. hauseri) and three unnamed

genomospecies 4, 5 and 6 [2,3]. Proteus rods are widespread

in the environment and make up part of the normal flora of

the human gastrointestinal tract. Proteus ranks third (after

Escherichia and Klebsiella) as the cause of uncomplicated

cystitis, pyelonephritis and prostatitis, particularly, in hos￾pital-acquired cases [4]. P. mirabilis accounts for approxi￾mately 3% of nosocomial infections in the United States

where, together with P. penneri, it may play a role in some

diarrhoeal diseases [5]. Recently, it has been suggested that

P. mirabilis may play an ethiopathogenic role in rheumatoid

arthritis [6].

According to the serological specificity of the O-chain

polysaccharides (O-antigens) of the lipopolysaccharides

(LPS), strains of P. mirabilis and P. vulgaris have been

classified into 60 O-serogroups [7,8], including 49 numbered

serogroups (O1 to O49) [7]. Recently, immunochemical

studies of LPS enabled establishment of a number of

additional serogroups for P. penneri strains [9–11]. The

serological heterogeneity of Proteus strains is associated

with a high diversity of the O-antigen composition and

structure [12,13]. A common structural feature of most

Proteus O-antigens studied so far is the presence of

hexuronic acids and their amides with amino acids, which

often serve as immunodominant groups [13].

Here, we report on the structure of a new acidic

O-polysaccharide from a nonclassified strain P. mirabilis

termed G1, which contains an amide of D-galacturonic acid

with L-lysine. Based on chemical and serological data, we

propose to classify this strain in Proteus serogroup O3.

MATERIALS AND METHODS

Bacterial strains and growth

P. mirabilis strains G1 and D52 were kindly provided by

J. Gmeiner (Institute for Microbiology and Genetics,

Darmstadt, Germany). Strain G1 was a clinical isolate

from urine of a woman with bacteriuria and could be

classified in none of 49 O-serogroups in the Kaufman–

Perch scheme of Proteus [7]. Biochemical properties of both

strains were checked in API 20E test, which showed 99.9%

identity with the P. mirabilis species. For other strains used

in this work, P. mirabilis O28 (51/57) was purchased from

the Czech National Collection of Type Cultures (CNCTC,

Institute of Epidemiology and Microbiology, Prague,

Czech Republic), and P. mirabilis S1959 (O3) and its R14

mutant (T-like form) came from the collection of the

Correspondence to Z. Sidorczyk, Department of General Microbio￾logy, Institute of Microbiology and Immunology, University of Lodz,

90–237, Lodz, Poland. Fax and Tel.: + 48 42 635 44 67,

E-mail: [email protected]

Abbreviations: EIA, enzyme immunosorbent assay; D-GalA(l-Lys),

Na

-(D-galacturonoyl)-L-lysine; D-GlcA, D-glucuronic acid; HMBC,

heteronuclear multiple-bond correlation; LPS, lipopolysaccharide;

ROESY, rotating-frame NOE spectroscopy.

(Received 15 October 2001, revised 2 January 2002, accepted

11 January 2002)

Eur. J. Biochem. 269, 1406–1412 (2002) Ó FEBS 2002