Somatic Serogroups, Capsular Types, and Species of Fecal Klebsiella in Patients with Ankylosing Spondylitis

Abstract

The purpose of the present study was to find out whether patients with ankylosing spondylitis (AS) carry fecal Klebsiellastrains that belong to serotypes or species specific for AS. Somatic serotypes (O groups), capsular (K) serotypes, and biochemically identified species were determined for fecal klebsiellae isolated from 187 AS patients and 195 control patients. The controls were patients with fibromyalgia or rheumatoid arthritis. The 638 isolates ofKlebsiella that were obtained represented 161 strains; 81 from AS patients and 80 from the controls. The average number ofKlebsiella strains per patient was 1.7 for the AS group and 1.5 for the control group. The most common O group was O1, which was observed for isolates from 23 of 187 AS patients and 24 of 195 control patients. Next in frequency was group O2, which was observed for isolates from 17 AS patients and 15 control patients. Regarding the K serotypes, 59 different types were identified, revealing a heterogeneous representation of Klebsiella strains, without a predominance of any serotype. By biochemical identification,Klebsiella pneumoniae was the most frequently occurring species, being found in 45 AS patients and 45 control patients. Next in the frequency was K. oxytoca, which was observed in 26 AS patients and in 29 control patients. K. planticola andK. terrigena occurred in only a minority of patients. Altogether, when analyzed either separately or simultaneously according to O groups, K serotypes, and biochemically identified species, no evidence of the existence of AS-specific Klebsiella strains was obtained. These findings do not indicate participation ofKlebsiella in the etiopathogenesis of AS.

Klebsiella typing: pulsed-field gel electrophoresis (PFGE) in comparison with O:K-serotyping

“…E. coli and O-, K-and H-typing) is known to produce a better discrimination. This study offers the second description [22] and the first evaluation of the use of O:K-serotyping for typing of Klebsiella.…”

Association between Klebsiella pneumoniae and ankylosing spondylitis: A systematic review and meta‐analysis

“…[Ig]G, IgM, IgA) against K. pneumoniae and AS, 17,18,[22][23][24][25][26][27][28][29]31,[35][36][37][38][39]42 and 8 studies evaluated the association between presence of K. pneumoniae in feces and AS. 15,30,[32][33][34]40,41,43 A proportion of studies (18/25) were conducted before 2000, and only 5 studies used matching method (eg, matched for age, gender, and ethnicity) to select participants in the control group. 18,23,30,36,39 There were 7 studies that selected only healthy people as controls, 18,28,30,34,39,41,42 and the control groups in other studies also included people with other diseases, such as rheumatoid arthritis or Crohn's disease.…”

“…Eight studies, 15,30,[32][33][34]40,41,43 involving 517 AS patients and 535 non-AS participants, reported the association between presence of K. pneumoniae in feces and AS. When compared with healthy people or non-AS patients, the pooled results showed the detection rate of K. pneumoniae in AS groups and control groups was similar (OR = 1.01; 95% CI: 0.77-1.34, I 2 = 36.8%) (Table 2).…”

“…Avakian et al 13 reported that anti‐HLA‐B27 allogeneic human tissue‐typing sera can bind more readily to Klebsiella than other HLA‐specific anti‐sera, and anti‐Klebsiella antibodies were found to bind more significantly to the synovial tissues of AS than in other rheumatic diseases 14 . On the other hand, these associations were not observed in other studies 15‐18 . Consequently, the association between K. pneumoniae and AS still remains controversial.…”

“…14 On the other hand, these associations were not observed in other studies. [15][16][17][18] Consequently, the association between K. pneumoniae and AS still remains controversial. To examine this issue, we conducted this systematic review and meta-analysis of all available evidence to evaluate whether K. pneumoniae infection is associated with AS.…”