Unique Features of a Highly Pathogenic
            <i>Campylobacter jejuni</i>
            Strain

Hofreuter, Dirk; Tsai, Jennifer; Watson, Robert O.; Novik, Veronica; Altman, Bill; Benitez, Michelle; Clark, Christina; Perbost, Clotilde; Jarvie, Thomas; Du, Lei; Galán, Jorge E.

doi:10.1128/iai.00210-06

Cited by 273 publications

(204 citation statements)

References 72 publications

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“…Selected restriction-modification (RM) genes of C. jejuni were inactivated via the allelic exchange using suicide plasmids as described previously (21). Specifically, Cj0031 and hsdR mutants were constructed by insertional mutation with a chloramphenicol resistance cassette (cat).…”

Section: Methodsmentioning

confidence: 99%

Heat Shock-Enhanced Conjugation Efficiency in Standard Campylobacter jejuni Strains

Zeng

Ardeshna

Lin

2015

Appl Environ Microbiol

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Campylobacter jejuni, the leading bacterial cause of human gastroenteritis in the United States, displays significant strain diversity due to horizontal gene transfer. Conjugation is an important horizontal gene transfer mechanism contributing to the evolution of bacterial pathogenesis and antimicrobial resistance. It has been observed that heat shock could increase transformation efficiency in some bacteria. In this study, the effect of heat shock on C. jejuni conjugation efficiency and the underlying mechanisms were examined. With a modified Escherichia coli donor strain, different C. jejuni recipient strains displayed significant variation in conjugation efficiency ranging from 6.2 ؋ 10 ؊8 to 6.0 ؋ 10 ؊3 CFU per recipient cell. Despite reduced viability, heat shock of standard C. jejuni NCTC 11168 and 81-176 strains (e.g., 48 to 54°C for 30 to 60 min) could dramatically enhance C. jejuni conjugation efficiency up to 1,000-fold. The phenotype of the heat shock-enhanced conjugation in C. jejuni recipient cells could be sustained for at least 9 h. Filtered supernatant from the heat shock-treated C. jejuni cells could not enhance conjugation efficiency, which suggests that the enhanced conjugation efficiency is independent of secreted substances. Mutagenesis analysis indicated that the clustered regularly interspaced short palindromic repeats system and the selected restriction-modification systems (Cj0030/Cj0031, Cj0139/Cj0140, Cj0690c, and HsdR) were dispensable for heat shock-enhanced conjugation in C. jejuni. Taking all results together, this study demonstrated a heat shock-enhanced conjugation efficiency in standard C. jejuni strains, leading to an optimized conjugation protocol for molecular manipulation of this organism. The findings from this study also represent a significant step toward elucidation of the molecular mechanism of conjugative gene transfer in C. jejuni.

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Section: Methodsmentioning

confidence: 99%

Heat Shock-Enhanced Conjugation Efficiency in Standard Campylobacter jejuni Strains

Zeng

Ardeshna

Lin

2015

Appl Environ Microbiol

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“…Only a few sequenced strains of these bacteria were isolated directly from dairy sources. Sequenced representatives include single B. cereus and L. monocytogenes strains isolated from cheese (Nelson et al, 2004;Rasko et al, 2005) and a highly virulent C. jejuni strain isolated from raw milk (Hofreuter et al, 2006).…”

Section: Genome Sequences Of Milk-associated Pathogens and Spoilage Bmentioning

confidence: 99%

Impact of bacterial genomics on determining quality and safety in the dairy production chain

Marco

Wells-Bennik

2008

International Dairy Journal

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“…The complete genome of IA3902 has been sequenced (19). C. jejuni NCTC 11168 and 81-176 are both human isolates (25,50), nonabortifacient, and genome sequenced and were used as controls. All C. jejuni strains were grown on Mueller-Hinton (MH) agar under microaerobic (5% oxygen, 10% carbon dioxide, and 85% nitrogen) conditions at 42°C for up to 48 h. When needed, the culture medium was supplemented with Campylobacter-selective agents and supplements (catalog no.…”

Section: Methodsmentioning

confidence: 99%

Key Role of Capsular Polysaccharide in the Induction of Systemic Infection and Abortion by Hypervirulent Campylobacter jejuni

et al. 2017

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Campylobacter jejuni is a zoonotic pathogen, and a hypervirulent clone, named clone SA, has recently emerged as the predominant cause of ovine abortion in the United States. To induce abortion, orally ingested Campylobacter must translocate across the intestinal epithelium, spread systemically in the circulation, and reach the fetoplacental tissue. Bacterial factors involved in these steps are not well understood. C. jejuni is known to produce capsular polysaccharide (CPS), but the specific role that CPS plays in systemic infection and particularly abortion in animals remains to be determined. In this study, we evaluated the role of CPS in bacteremia using a mouse model and in abortion using a pregnant guinea pig model following oral challenge. Compared with C. jejuni NCTC 11168 and 81-176, a clone SA isolate (IA3902) resulted in significantly higher bacterial counts and a significantly longer duration of bacteremia in mice. The loss of capsule production via gene-specific mutagenesis in IA3902 led to the complete abolishment of bacteremia in mice and abortion in pregnant guinea pigs, while complementation of capsule expression almost fully restored these phenotypes. The capsule mutant strain was also impaired for survival in guinea pig sera and sheep blood. Sequence-based analyses revealed that clone SA possesses a unique CPS locus with a mosaic structure, which has been stably maintained in all clone SA isolates derived from various hosts and times. These findings establish CPS as a key virulence factor for the induction of systemic infection and abortion in pregnant animals and provide a viable candidate for the development of vaccines against hypervirulent C. jejuni. KEYWORDS Campylobacter, capsule, systemic infection, abortion, sheep, bacteremiaA s a zoonotic pathogen, Campylobacter is a leading cause of bacterial foodborne gastroenteritis in humans (1). In addition, Campylobacter species have been recognized as one of the most common causes of ovine abortion in the United States and worldwide, with an overall abortion rate of 5 to 50% in affected flocks (2). As a consequence, Campylobacter poses a significant economic burden on sheep producers and greatly impacts sheep health and welfare. A national study, NAHMS Sheep 2001, conducted by the USDA/APHIS/Veterinary Services in collaboration with the American Sheep Industry Association revealed that Campylobacter species ranked first among all infectious causes of abortion within the last 3 years of the study, with 53.7% of the reported cases being confirmed by a veterinarian or diagnostic laboratory (3).Historically, Campylobacter fetus subsp. fetus accounted for the majority of the Campylobacter spp. associated with ovine abortion; however, we recently discovered a remarkable shift in the etiology of the disease (4, 5). Specifically, a highly virulent

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Unique Features of a Highly Pathogenic Campylobacter jejuni Strain

Cited by 273 publications

References 72 publications

Heat Shock-Enhanced Conjugation Efficiency in Standard Campylobacter jejuni Strains

Heat Shock-Enhanced Conjugation Efficiency in Standard Campylobacter jejuni Strains

Impact of bacterial genomics on determining quality and safety in the dairy production chain

Key Role of Capsular Polysaccharide in the Induction of Systemic Infection and Abortion by Hypervirulent Campylobacter jejuni

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