title: Identification of and screening for human Helicobacter cinaedi infections and carriers via nested PCR.
abstract: Helicobacter cinaedi is the most frequently reported enterohepatic Helicobacter species isolated from humans. Earlier research suggested that certain patients with H. cinaedi infection may remain undiagnosed or incorrectly diagnosed because of difficulties in detecting the bacteria by conventional culture methods. Here, we report a nested PCR assay that rapidly detects the cytolethal distending toxin gene (cdt) of H. cinaedi with high specificity and sensitivity. Specificity of the assay was validated by using different species of Helicobacter and Campylobacter, as well as known H. cinaedi-positive and -negative samples. The sensitivity of detection for the cdt gene in the assay was 10(2) CFU/ml urine or 10(2) CFU/10(5) infected RAW 264.7 cells. In an H. cinaedi-infected mouse model, the cdt gene of H. cinaedi was effectively detected via the assay with urine (6/7), stool (2/3), and blood (2/6) samples. Importantly, it detected H. cinaedi in blood, urine, and stool samples from one patient with a suspected H. cinaedi infection and three patients with known infections. The assay was further used clinically to follow up two H. cinaedi-infected patients after antibiotic treatment. Stool samples from these two patients evaluated by nested PCR after antibiotic therapy showed clearance of bacterial DNA. Finally, analysis of stool specimens from healthy volunteers showed occasional positive reactions (4/30) to H. cinaedi DNA, which suggests intestinal colonization by H. cinaedi in healthy subjects. In conclusion, this nested PCR assay may be useful for the rapid diagnosis, antimicrobial treatment evaluation, and epidemiological study of H. cinaedi infection.
authors.affiliation: Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Kohta
authors.initials: K
authors.lastname: Oyama
authors.forename: Shahzada
authors.initials: S
authors.lastname: Khan
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Okamoto
authors.forename: Shigemoto
authors.initials: S
authors.lastname: Fujii
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Ono
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Matsunaga
authors.forename: Jun
authors.initials: J
authors.lastname: Yoshitake
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Sawa
authors.forename: Junko
authors.initials: J
authors.lastname: Tomida
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kawamura
authors.forename: Takaaki
authors.initials: T
authors.lastname: Akaike
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics; D001431:Bacteriological Techniques / Q000379:methods*; D001769:Blood / Q000382:microbiology; D002353:Carrier State / Q000175:diagnosis*; D004195:Disease Models, Animal; D005243:Feces / Q000382:microbiology; D005260:Female; D016998:Helicobacter / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D016481:Helicobacter Infections / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D051379:Mice; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014556:Urine / Q000382:microbiology; D055815:Young Adult
chemical_list: D001427:Bacterial Toxins; C067044:cytolethal distending toxin