The Absence of Cecal Colonization of Chicks by a Mutant of Campylobacter jejuni Not Expressing Bacterial Fibronectin-Binding Protein

Abstract

Campylobacter jejuni is a common cause of human gastrointestinal illness throughout the world. Infections with C. jejuni and Campylobacter coli are frequently acquired by eating undercooked chicken. The ability of C. jejuni to become established in the gastrointestinal tract of chickens is believed to involve binding of the bacterium to the gastrointestinal surface. A 37-kD outer membrane protein, termed CadF, has been described that facilitates the binding of Campylobacter to fibronectin. This study was conducted to determine whether the CadF protein is required for C. jejuni to colonize the cecum of newly hatched chicks. Day-of-hatch chicks were orally challenged with C. jejuni F38011, a human clinical isolate, or challenged with a mutant in which the cadF gene was disrupted via homologous recombination with a suicide vector. This method of mutagenesis targets a predetermined DNA sequence and does not produce random mutations in unrelated genes. The parental C. jejuni F38011 readily colonized the cecum of newly hatched chicks. In contrast, the cadF mutant was not recovered from any of 60 chicks challenged, indicating that disruption of the cadF gene renders C. jejuni incapable of colonizing the cecum. CadF protein appears to be required for the colonization of newly hatched leghorn chickens.

PCR Detection of Four Virulence-Associated Genes of Campylobacter jejuni Isolates from Thai Broilers and Their Abilities of Adhesion to and Invasion of INT-407 Cells

“…Some genes are involved in Campylobacter adhesion and invasion. Four mutant strains derived from F38011, an excellent colonizer of chicken caeca, dnaJ, cadF, pldA and ciaB are incapable of colonizing the ceca [20,23,43,44]. cadF (Campylobacter adhesin to fibronectin) is an outer membrane protein, which encodes a protein that interacts with a host extracellular matrix protein fibronectin [31], and is required for Campylobacter adherence to and colonization of the host cell surface [20].…”

“…Other genes such as ciaB (Campylobacter invasive antigen B) [21,34] and pldA encoded outer membrane phospholipase A [34] are involved in host cell invasion and are important for caecal colonization [21,43]. The ciaB, pldA and dnaJ (heat shock protein) genes are important to caecal colonization and mutations of these genes severely limit the ability of the mutant strains to colonize the chicken caeca [20,43,44]. The objective of this study was to study the prevalence of C. jejuni in Thai broiler caeca and their ability to adhere and invade and the presence of the 4 genes that are involved in the adherence and invasion of the Campylobacter in the INT-407 cell culture model.…”

Caracterização molecular de linhagens de Campylobacter coli isoladas de origens diversas

“…Estudos utilizando mutantes demonstraram que a ausência das proteínas codificadas por esses genes reduziu a capacidade de colonização dessas bactérias Ziprin et al, 1999;Muller et al, 2006).…”

“…Acredita-se que haja o envolvimento de CDT no processo de diarreia causando alterações na cripta epitelial, o que leva à uma erosão temporária e subsequente perda na função de absorção (Ziprin et al, 1999;van Vliet;Ketley, 2001;Osek, 2008). Outra toxina descrita para algumas espécies de Campylobacter é a hemolisina, que possui a capacidade de promover a lise dos eritrócitos (Man, 2011).…”

“…Da mesma maneira, estudos com mutantes demonstraram que a deficiência na produção da proteína CadF (Campylobacter adhesion to fibronectin) torna a bactéria incapaz de colonizar o intestino do frango, fato esse que pode ser facilmente explicado, pois a CadF é uma proteína de membrana externa que auxilia o processo de adesão de Campylobacter coli as células do epitélio intestinal Ziprin et al, 1999). Outros genes relacionados ao processo de adesão foram encontrados em um número menor de linhagens, no presente estudo, como podemos observar pela análise dos genes dnaJ e docA que foram encontrados em 10 (15,9%) e duas (3,2%) linhagens de Campylobacter coli, respectivamente.…”