Current Perspectives on Campylobacter Ecology

CURRENT PERSPECTIVES ON CAMPYLOBACTER ECOLOGY

Irene HanningAssistant ProfessorUniversity of TennesseeDepartment of Food Science and Technologye-mail [email protected]

Campylobacter•Leading cause of foodborne bacterial illness

•Non-robust pathogen

•Susceptible to most stresses•Temperature

•pH

•Desiccation

•Colonizes poultry as a commensal

•Colonizes the gastrointestinal tract of poultry about 2 to 3 wks of age

Campylobacter

Colonizes the gastrointestinal tract about 2 to 3 wks of age?

Gut development

•Histological development

•Mucus layer

•Microbial colonization

Histological development

•Early absorption of yolk sac stimulates peristalsis, microvilli development, and mucus secretion

•Lengthening of the villi promoted by feed intake due to a need for increase surface area for absorption of nutrients

•Delayed access to first feed causes a reduction in the villus surface area, particularly in the jejunum (Geyra et al., 2001).

Histological development• Ecology of microflora impacts histology of the GI tract

• Germ-free birds show reduction in relative weight and length of intestines.

• Altered amounts of lamina propria, lymphoid tissue, reticuloendothelial cells, intestinal weight and moisture in germ-free birds (Stutz et al. 1983).

Mucus layer

•Provides innate immunity

•Forms supportive and protective barrier

•Development is influenced by access to feed post-hatch

•Highly glycosolayted mucins provide attachment sites for microflora

Mucus layer

Mucus production begins at 3d prior to hatch

Mucus layer

Campylobacter colonizes deep in the mucin layer

•Forms protective barrier

•Creates a microaerophilic niche

•Campylobacter can utilize mucin as a carbon source

•Chemoattractant

Intestinal community

• Educate the immune system• Protection from pathogen colonization• Taking up space• Production of antimicrobial substances

• Synthesize vitamins• Breakdown indigestible substances• Reduce allergic responses• Impact nutrient acquisition

Intestinal community

•Campylobacter does not possess genes for phosphofructokinase

•Community dependent because it needs secondary metabolites

•Community stimulates production of mucin

CampylobacterDynamics of the intestinal community

Campylobacter

Campylobacter colonizes the gastrointestinal tract about 2 to 3 wks of age because…..

•Gut development

•Microaerophilic environment

•Community dependent

•No phosphofructokinase

CampylobacterHow is Campylobacter affected by the community?

How does Campylobacter change with the community

Microbial Populations

• Gene transfer

• Quorum sensing

• Resistance

• Gut fermentation

• Degradation

• Cooperation

• Competition

• Predation

Functions and Actions

Microbial Populations

•Biofilms

•Spoilage

•Soil

•Water microcosms

•GutLocation, location, location……

Biofilms

•Support susceptible

organisms

•Resist environmental

stresses

•Quorum sensing

(intra and inter-

species

communication

Campylobacter

Campylobacter

•Diversity in genotypes increases over rearing period

•C. jejuni is replaced by C. coli

Campy and the community

0

20

40

60

80

100C. je-juniC. coli

CampylobacterHow is Campylobacter affected by the intestinal community?

How does Campylobacter change with the intestinal community?

Antibiotics• Tend to “stabilize” the gut populations

• Antibiotics reduce the relative weight and length of the intestines (Visek, 1978; Postma et al., 1999).

• Increase growth rate• Improve health• Reduce infections

Campylobacter gains resistance from the community

• Growth promoter in poultry production

• Controls coccidiosis

• Bioconverted to arsenate (AsV) and arsenite (AsIII) in poultry litter

• Birds ingest arsenic compounds while pecking at the litter

Roxersone

Campylobacter gains resistance from the environment

• Fluoroquinolones used in poultry production

• Results in Cipro-resistant Campylobacter

• Banned in 2005

• Resistance conferred fitness in the absence of selection pressure……

……..Hence persistence of resistance

Campylobacter gains resistance from the environment

• Tylosin – a macrolide used in chickens as therapeutic/prophylactic agents for the control of chronic respiratory diseases caused by mycoplasmas and as subtherapeutic agents for improving growth rates and feed efficiency

• At 0.53 g/L of water -reduced Campy and no resistance obtained

• At 0.05g /Kg of feed – Campy resistance emerged

• Highly resistant strains with mutation in the 23S RNA gene

• Lower resistance levels no mutation, utilized CmeABC efflux pump

Campylobacter control efforts

Preharvest• Antibiotics• Direct fed antimicrobials• Probiotics• Vaccination• Bacteriocins

Campylobacter control efforts

•Should be targeted at the production level

•Affordable

•How and when?

•If we target C. jejuni will we leave a niche for C. coli?

•Candidate genes should be conserved among strains

Vaccines

Campylobacter

Direct Fed Antimicrobials

Campylobacter control efforts

Belguim study reports lowering load of Campylobacter by 2 logs would reduce the number of cases by 84% (Messens et al. 2007)

Danish study reports 2 logs can reduce incidences by 97% (Rosenquist et al. 2003)

Campylobacter control efforts

• Increase scalding water temperature• Improve evisceration techniques• More water during processing• Forced air-chilling• Disinfectants in the water………….Reducing exposure of carcasses to fecal materials

Consumer food safety

Consumer food safety

Food safety in the home

Campylobacter control efforts

Pre-Harvestantimicrobials, vaccines, probiotics, etc..

ProcessingAntimicrobials, temperature, etc..

ConsumerEducation

Post-HarvestPackagingTemperature

AcknowledgementsU of Arkansas

• Poultry Science• Mike Slavik• Dan Donoghue• John Marcy• Yan-Bin Li• Casey Owens• Billy Hargis• Hong Wang• Geetha Kumar• Ann Woo-ming

• Food Science• Steve Ricke• Phil Crandall• John-Francios Meullenet• Latha Devereddy• Sun-Yook Lee

• Biological Sciences• David McNabb• Ines Pinto• Carmen Padilla

• Chemistry• Roger Koeppe

• Animal Sciences• Charlie Rosenkrans

• Plant Sciences• Ken Korth• Carlos Avilos

• UTK• Qixin Zhong• Michael Davidson• Ann Draughon• David Golden• John Mount• Frederico Harte• William Morris• Doris D’Souza• Dwight Loveday• Jennifer Richards• Svetlana Zivanovic• Chayapa

Techathuvanan• Bill Brown• Steve Oliver

• Chicago Field Museum• Jacques Hill

• U of Delaware• Mark Parcells

• U of Minnesota• Tim Johnson• Randall Singer

• MIT• Eric Alm• Arne Materna• Lawrence David

• Cobb-Vantress• Robin Jarquin• Joe Schultz

• Tyson Foods, Inc.• John

• Pel-Freeze• Regina Stowe

• Gerber Products• Melanie Reed• Rama Holloway• Susan Allen• Jarius David

• Cargill• Brian Woo-ming

• USDA• Ann Donoghue• Bill Huff• Jerri Huff• Naryan Rath

• FDA• Rajesh Nayak• Steve Foley• Jin Han

Thank You!