Molecular Epidemiologic Analysis and Antimicrobial Resistance of Helicobacter cinaedi Isolated from Seven Hospitals in Japan

Abstract

cHelicobacter cinaedi colonizes the colons of human and animals and can cause colitis, cellulitis, and sepsis in humans, with infections in immunocompromised patients being increasingly recognized. However, methods for analyzing the molecular epidemiology of H. cinaedi are not yet established. A genotyping method involving multilocus sequence typing (MLST) was developed and used to analyze 50 H. cinaedi isolates from Japanese hospitals in addition to 6 reference strains. Pulsed-field gel electrophoresis (PFGE) results were also compared with the MLST results. Based on the genomic information from strain CCUG18818, 21 housekeeping genes were selected as candidates for MLST and were observed to have high homology (96.5 to 100%) between isolates. Following a comparison of the 21 housekeeping genes from 8 H. cinaedi isolates, 7 genes were chosen for MLST, revealing 14 sequence types (STs). The isolates from 3 hospitals belonged to the same STs, but the isolates from the other 4 hospitals belonged to different STs. Isolates belonging to ST6 were analyzed by PFGE and showed similar, but not identical, patterns between isolates. Isolates belonging to ST9, ST10, and ST11, which belonged to the same clonal complex, had the same pattern. All isolates were found to contain mutations in GyrA and the 23S rRNA gene that confer ciprofloxacin and clarithromycin resistance, respectively, in H. cinaedi. These results raise concerns about the increase in H. cinaedi isolates resistant to clarithromycin and ciprofloxacin in Japan.

Helicobacter cinaedi and Helicobacter fennelliae Transmission in a Hospital from 2008 to 2012

“…We developed a multilocus sequence typing (MLST) method for H. cinaedi strains by comparing the results of MLST and pulsed-field gel electrophoresis (PFGE) and confirmed that most H. cinaedi isolates from this outbreak were identical (13). After the outbreak, we isolated Helicobacter spp.…”

“…During 2008 to 2012, 46 H. cinaedi isolates were obtained from different inpatients. Twelve H. cinaedi isolates were obtained in 2008; these were described previously (13). Since then, 12, 16, and 5 isolates were obtained in 2009, 2010, and 2011, respectively, and 1 H. cinaedi isolate was obtained in 2012; these are described here.…”

“…MLST was performed as described previously (13). All se- We previously demonstrated that the CC9 strains possessed the same PFGE pattern (13).…”

Multilocus Sequence Typing of the Porcine and Human Gastric Pathogen Helicobacter suis

“…Keeping in mind that H. suis isolation remains extremely difficult and time-consuming, we decided to develop an MLST technique which can be applied on samples without the need for in vitro cultivation. As a genotyping method and technique, MLST has often been used in strain typing studies and can be considered a gold standard (15,18,(20)(21)(22). For MLST analysis of strains of H. pylori, a closely related major human gastric pathogen, 7 housekeeping genes are used (atpA, efp, mutY, ppa, trpC, yphC, and ureI) (17,19).…”

“…However, given the extremely fastidious nature of this microorganism, a culture-independent method should be used, allowing typing of H. suis directly in stomach samples. Multilocus sequence typing (MLST), introduced in 1998, has been widely used in molecular epidemiology and population biology of bacterial species (13)(14)(15)(16) and has proven its usefulness for typing strains of other Helicobacter species (17)(18)(19). In addition, this technique uses the unambiguousness and portability of nucleotide sequence data, which allows results from different laboratories to be compared without exchanging strains (20)(21)(22).…”