The Vibrio cholerae Mannose-Sensitive Hemagglutinin Is the Receptor for a Filamentous Bacteriophage from V. cholerae O139

Abstract

We previously isolated from a 1994 isolate of Vibrio cholerae O139 a filamentous lysogenic bacteriophage, choleraphage 493, which inhibits pre-O139 but not post-O139 El Tor biotype V. cholerae strains in plaque assays. We investigated the role of the mannose-sensitive hemagglutinin (MSHA) type IV pilus as a receptor in phage 493 infection. Spontaneous, Tn5 insertion, andmshA deletion mutants are resistant to 493 infection. Susceptibility is restored by mshA complementation of deletion mutants. Additionally, the 493 phage titer is reduced by adsorption with MSHA-positive strains but not with a ΔmshA1 strain. Monoclonal antibody against MSHA inhibits plaque formation. We conclude that MSHA is the receptor for phage 493. The emergence and decline of O139 in India and Bangladesh are correlated with the susceptibility and resistance of El Tor strains to 493. However, mshA gene sequences of post-O139 strains are identical to those of susceptible pre-O139 isolates, indicating that phage resistance of El Tor is not due to a change in mshA. Classical biotype strains are (with rare exceptions) hemagglutinin negative and resistant to 493 in plaque assays. Nevertheless, they express the mshA pilin gene. They can be infected with 493 and produce low levels of phage DNA, like post-O139 El Tor strains. Resistance to 493 in plaque assays is thus not equivalent to resistance to infection. The ability of filamentous phages, such as 493, to transfer large amounts of DNA provides them, additionally, with the potential for quantum leaps in both identity and pathogenicity, such as the conversion of El Tor to O139.

Molecular genetic basis of biofilm formation as a component of Vibrio Cholerae persistence in water reservoirs of Russian Federation

“…Однако обращает на себя внимание неожиданно быстрая адгезия классического штамма Р-17917 (1 сут), в отличие от использованного для сравнения 569B (5 сут). Считается, что классические штаммы, хотя и синтезируют субъединицы MSHA, не собирают из них пили на поверхности клеток, однако из этого правила встречаются исключения [16][17][18], и, возможно, этот штамм является одним из таких исключений. Поэтому мы дополнительно проверили промоторную область обоих msh-оперонов, использовав в качестве эталонных таковые референс-штамма [9].…”

“…Учитывая, что аналогичная SNP в промоторной области гена tdh V. parahaemolyticus приводит к резкому снижению экспрессии гена [19], можно предположить, что у V. cholerae она способна вызвать такой же эффект. Не исключено, что описанный в [17] спонтанный мутант классического штамма, образующий MSHA, как раз и является мутантом именно по этой SNP, как и штамм Р-17917. У последнего с 771 до 579 п. н. был укорочен ген msho как следствие делеции G-465, приведшей к сдвигу рамки считывания (FS -frame shift) и образованию преждевременного стоп-кодона (PSC -premature stop codon), но его продукт сохранил домен пилина.…”

Diversification of the type IV filament super-family into machines for adhesion, secretion, DNA transformation and motility

“…The TFF-SF nanomachines assemble filaments composed of subunits with an N-terminal sequence motif named class III signal peptide, generically named type IV pilins [17]. These systems are involved in functions typically associated with extracellular pili in Prokaryotes, including adherence, cell-cell attachment, the formation of biofilms, and are exploited by phages for cell infection [21–23]. The T4aP, T2SS, T4bP, and Tad, are also important virulence factors in pathogenic bacteria [24–29].…”

Two different mechanisms of ampicillin resistance operating in strains ofVibrio choleraeO1 independent of resistance genes

“…In V. cholerae O1 and O139, type IV fimbriae consist of a homologous polypeptide formed from fimbrillin (pilin), a 17-kDa protein encoded by the fimA (mshA) gene (Ehara et al, 1994;Jonson et al, 1994). Some type IV fimbriae serve as receptors for filamentous phages (Ehara et al, 1997;Shimodori et al, 1997;Jouravleva et al, 1998) and are thought to play a role in bacterial adherence to epithelial cells and mucosal surfaces. Type IV fimbriae also play important roles in twitching motility or social gliding by the retraction and extension of fimbriae (Shi & Sun, 2002).…”