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Three severe acute gastroenteritis patients were identified within a 5-h period in a sentinel hospital enrolled in the foodborne pathogen surveillance project in Beijing. All patients had high fever (over 38.5°C), diarrhea, abdominal pain, vomiting, and headache. Ten grams of fresh patient stool sample and 25 g of six suspected foods were collected for real-time PCR screening for 10 major pathogens. Bacterial isolation was performed. Pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and antibiotic susceptibility tests were conducted for all the isolates. Whole-genome sequences of the three Campylobacter coliisolates were compared using whole-genome MLST. All stool samples were positive for C. coli,as revealed by PCR. Eleven of the C. coliisolates had the same PFGE and ST type. All isolates were resistant to nalidixic acid, ciprofloxacin, streptomycin, and tetracycline, consistent with the findings of the in silicoantibiotic resistance gene profiling. Most coding sequences (99%, 1736/1739) were identical among the three sequenced isolates, except for three frameshift-mutated genes caused by the simple sequence repeats (poly-Gs). This was likely a single-source outbreak caused by a group of highly clonal C. coli. This was the first outbreak of severe gastroenteritis caused by C. coliin China.

AbstractThe aim of this study was to determine the molecular subtyping and antimicrobial susceptibility characteristics of Campylobacter coliisolates from different sources in China. One hundred thirteen C. coliisolates were subtyped by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and porAand flaAshort variable region (SVR) nucleotide sequences. Cluster analysis was performed based on the PFGE and sequence types (ST). Eighty-four PFGE patterns (SmaI) were observed in 113 isolates. Fifty-four STs (28 novel) and three clonal complexes (CC), 86% of which were clustered to CC828, were observed, as well as 52 porAand 37 flaA-SVR sequence alleles. MLST, porA, and flaA-SVR analysis demonstrated that many isolates from diarrheal patients shared identical genotypes with chicken isolates. Minimum inhibitory concentration values of 10 antibiotics were analyzed for 109 isolates isolated in 2011 using the E-test method. The most frequently observed resistance agents were nalidixic acid (100%) and ciprofloxacin (100%), followed by levofloxacin (99%), tetracycline (94%), metronidazole (93%), erythromycin (61%), streptomycin (72%), gentamicin (59%), ampicillin (50%), and chloramphenicol (29%). Multidrug resistance was detected in 108 of 109 C. coliisolates (99%).

AbstractFourteen Campylobacter jejunigenes—porA, cadF, omp18, dnaK, flaC, peb1, peb2, peb3, peb4, ahpC, groEL, tuF, hipO,and Cj0069—were cloned and expressed in Escherichia coliBL21. The recombinant proteins were purified on histidine (His) and glutathione S–transferase (GST) trap columns using the ÄKTA Explorer 100 System. Recombinant proteins were visualized using sodium dodecyl sulfate–polyacrylamide gel electrophoresis and identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The antigenicities of these recombinant proteins were assessed by Western blotting and enzyme-linked immunosorbent assays with anti–C. jejuniimmune rabbit sera. Four recombinant proteins, including rGST-PorA, rHis-CadF, rGST-GroEL, and rGST-TuF, demonstrated reactions with both anti-serum and preimmune serum, while rHis-DnaK, rGST-FlaC, rGST-PEB2, rGST-PEB3, rGST-PEB4, and rGST-HipO showed variable antigenicity characteristics to the anti-sera derived from different C. jejunistrains. rHis-Omp18, rHis-PEB1, and rGST-AhpC demonstrated universal and specific antigenities with the entire anti-sera panel tested in this present study, while recombinant rGST-Cj0069 and rHis-DnaK did not react with any of the anti–C. jejunisera tested. In conclusion, rGST-AhpC may be useful as a potential serodiagnostic antigen for C. jejuniinfection.

AbstractFrom June to July 2007, 36 cases of Guillain-Barre syndrome (GBS) occurred in a township in north China. Serological study and bacteria culture were performed to investigate the association between preceding Campylobacter jejuniinfection and this GBS outbreak. Anti–C. jejuniantibodies were found in significantly higher numbers of GBS patients (IgM 84%, IgG 87.5%) than in healthy inspection cases (IgM 33%, IgG 27%). IgG anti-GM1 was the dominant anti-ganglioside antibody among the GBS patients. Seven C. jejuniisolates (four from human stool and three from poultry specimens taken from the patients' houses) were obtained. Serotyping and molecular analysis were used to investigate the genetic relatedness among these C. jejuniisolates. The four human isolates, collected from residents of the same district, were indistinguishable by both pulsed-field gel electrophoresis and multilocus sequence typing, suggesting these patients had a common source of infection. A new sequence type, sequence type-2993, was assigned to the human C. jejuniisolates, three of which belonged to Penner serotype heat-stable (HS):41. Both serotype and molecular subtype of the human C. jejuniisolates were different from those of isolates obtained from poultry specimens. Our results suggest that the antecedent C. jejuniinfection triggered this GBS outbreak in China.