Microbiology – Campylobacter Jejuni

Staining and Microbiologic Features:  

• C. Jejuni is an S-shaped rod that is non-spore forming and exhibits gram-negative staining [1].
• C. Jejuni flourishes in an environment with lowered oxygen levels (5-7%) and heightened carbon dioxide levels (5-10%), with optimal growth observed at 42°C compared to 37°C [2].
• Unlike other gram-negative bacteria that exhibit cell wall lipopolysaccharides (LPS) with endotoxin activity, C. jejuni expresses lipooligosaccharides.
• It tests positive for oxidase and catalase [3].
• The single polar flagellum of C. jejuni helps in its motility [1].
• Reservoirs for C. Jejuni include poultry and wild domestic animals [4].
• C. Jejuni is considered acid-sensitive, making it susceptible to the acidic conditions of the stomach. Consequently, it requires a high infective dose (about 104organisms) to initiate an infection in the intestine [3].

Virulence:  

• Similar to E. coli, C. Jejuni produces enterotoxin (LT toxin) [5].
• It produces cytotoxin that damages the intestinal mucosa [5].
• H antigen is another important virulence factor for C. Jejuni [4].

Transmission:  

• Transmission occurs through the fecal-oral route [4] 
• Consumption of unpasteurized milk and uncooked poultry [4]

Diseases and Complications:  

• Diarrhea: The patient can present with fever, headache, abdominal cramps, and bloody diarrhea [6].
• Some strains of C. Jejuni (especially serotype O:19) are associated with Guillain-Barré Syndrome. Antibodies produced during infection cross-react with peripheral nerves and lead to autoimmune-induced demyelination, resulting in Guillain-Barré Syndrome (GBS) symptoms [7].
• Some patients (particularly with HLA-B27 phenotype) can also develop Reactive Arthritis after C. Jejuni infection [7].

Diagnostic Testing:  

Campylobacter jejuni colonies” by Stefan Walkowski is licensed under CC BY-SA 4.0.

• Immunoassays for antigen detection [8]
• Nucleic Acid Amplification Tests (NAATs) [8]

 References: 

1 Jawetz, Melnick, & Adelberg’s Medical Microbiology Twenty-Seventh Edition (page no: 256)

2 Medical Microbiology by Patrick R. Murray Ph.D., Ken Rosenthal Ph.D., Michael A. Pfaller MD, 8th edition (page no: 281)

3 Jawetz, Melnick, & Adelberg’s Medical Microbiology Twenty-Seventh Edition (page no: 257)

4 CMMRS edition 6, 2016-17 (page no: 86)

5 CMMRS edition 6, 2016-17 (page no: 81)

6 CMMRS edition 6, 2016-17 (page no: 80)

7 Medical Microbiology by Patrick R. Murray Ph.D., Ken Rosenthal Ph.D., Michael A. Pfaller MD, 8th edition (page no: 282)

8 Medical Microbiology by Patrick R. Murray Ph.D., Ken Rosenthal Ph.D., Michael A. Pfaller MD, 8th edition (page no: 283)