Using three reference strains of Brachyspira hyodysenteriae (B204, B234, B169), one B. pilosicoli (P43/6/78), one B. murdochii (56-150), one B. intermedia (PWS/A), one B. innocens (B256) and ten Korean isolates, PCR-RFLP analysis of DNA encoding 23S rRNA was performed to establish a rapid and accurate method for characterizing porcine intestinal spirochetes. Consequently, B. hyodysenteriae and B. pilosicoli revealed different restriction patterns; however, the other three species shared the same pattern. These findings are not consistent with a prior report. Differences in 23S rRNA gene sequences, between two B. murdochii strains, 56-150 and 155-20, were observed. These results indicate that 23S rRNA PCR-RFLP could be used as an identification method for pathogenic Brachyspira spp. (B. hyodysenteriae and B. pilosicoli) as well as an epidemiological tool for characterizing spirochetes isolated from swine.
Animals ; DNA, Bacterial/genetics ; Dysentery, Bacillary/diagnosis/microbiology/*veterinary ; Korea ; Phylogeny ; Polymerase Chain Reaction/methods/*veterinary ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 23S/chemistry/*genetics ; Spirochaetales/*genetics/*isolation&purification ; Spirochaetales Infections/diagnosis/microbiology/*veterinary ; Swine ; Swine Diseases/diagnosis/*microbiology

We report a case of CTX-M-55-type extended-spectrum beta-lactamase (ESBL)-producing Shigella sonnei infection in a 27-year-old Korean woman who had traveled to China. The patient was admitted to the hospital due to abdominal pain, watery diarrhea, and fever (39.3degrees C). S. sonnei was isolated from her stool specimens, and the pathogen was found to be resistant to cefotaxime due to CTX-M-55-type ESBL. Insertion sequence (IS)Ecp1 was found upstream of the blaCTX-M-55 gene. The blaCTX-M-55 gene was transferred from the S. sonnei isolate to an Escherichia coli J53 recipient by conjugation. Pulsed-field gel electrophoresis and Southern blotting revealed that the blaCTX-M-55 gene was located on a plasmid of approximately 130 kb.
Adult ; Anti-Bacterial Agents/pharmacology ; Asian Continental Ancestry Group ; Cefotaxime/pharmacology ; China ; Drug Resistance, Bacterial/drug effects ; Dysentery, Bacillary/diagnosis/*microbiology ; Electrophoresis, Gel, Pulsed-Field ; Escherichia coli/metabolism ; Feces/microbiology ; Female ; Humans ; Plasmids/chemistry/genetics ; Republic of Korea ; Shigella sonnei/enzymology/*isolation & purification ; Travel ; beta-Lactamases/genetics/*metabolism

BACKGROUND: Shigella is a frequent cause of bacterial dysentery in the developing world. Treatment with antibiotics is recommended for shigellosis, but the options are limited due to globally emerging resistance. This study was conducted to determine the frequency and pattern of antimicrobial susceptibility of Shigella in China. METHODS: We studied the antimicrobial resistance profiles of 308 Shigella spp. strains (260 S. flexneri, 40 S. sonnei, 5 S. boydii, and 3 S. dysenteriae) isolated from fecal samples of patients (age, from 3 months to 92 yr) presenting with diarrhea in different districts of Anhui, China. The antimicrobial resistance of strains was determined by the agar dilution method according to the CSLI guidelines. RESULTS: The most common serogroup in the Shigella isolates was S. flexneri (n=260, 84.4%), followed by S. sonnei (n=40, 13.0%). The highest resistance rate was found for nalidixic acid (96.4%), followed by ampicillin (93.2%), tetracycline (90.9%), and trimethoprim/sulfamethoxazole (80.8%). Among the isolates tested, 280 (91.0%) were multidrug resistant (resistant to > or =2 agents). The most common resistance pattern was the combination of ampicillin, tetracycline, and trimethoprim/sulfamethoxazole (70.8%). Resistance to ampicillin and tetracycline were more common among S. flexneri than among S. sonnei isolates. CONCLUSIONS: S. flexneri is predominant in Anhui, China, and its higher antimicrobial resistance rate compared with that of S. sonnei is a cause for concern. Continuous monitoring of resistance patterns is necessary to control the spread of resistance in Shigella. The recommendations for antimicrobial treatment must be updated regularly based on surveillance results.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Ampicillin/pharmacology ; Anti-Infective Agents/*pharmacology ; Child ; Child, Preschool ; China ; Drug Resistance, Bacterial/drug effects ; Dysentery, Bacillary/*diagnosis/microbiology ; Feces/microbiology ; Humans ; Infant ; Microbial Sensitivity Tests ; Middle Aged ; Nalidixic Acid/pharmacology ; Shigella/*drug effects/isolation & purification ; Shigella flexneri/drug effects/isolation & purification ; Shigella sonnei/drug effects/isolation & purification ; Tetracycline/pharmacology ; Time Factors ; Trimethoprim-Sulfamethoxazole Combination/pharmacology ; Young Adult