Antimicrobial Resistance Patterns and Corresponding Multilocus Sequence Types of theCampylobacter jejuniIsolates from Human Diarrheal Samples

Abstract

A total of 121 Campylobacter isolates from 4,788 humans with gastroenteritis were identified and characterized by biochemical detection methods, polymerase chain reaction, and multilocus sequence typing (MLST). These samples were obtained during a 3-year period, from January 2007 to December 2009, using the National Notifiable Diseases Surveillance System at the Research Institute of Public Health and Environment in Seoul Metropolitan, Korea. Antimicrobial susceptibilities of the bacterium were also determined with the agar dilution method. All 121 isolates were identified as Campylobacter jejuni, with all (100%) of them having two virulence genes (ceuE and cadF) and a toxin gene (cdtB). Twenty-three different sequence types (STs), including 9 new STs, were determined by MLST. The most prevalent ST and clonal complex (CC) observed in this study were ST-45 (28.9%) and ST-45 CC (53.7%), respectively. Percentages of antimicrobial-resistant isolates were 1.9% for ampicillin, 0.8% for chloramphenicol, 24% for ciprofloxacin, 46.3% for enrofloxacin, 0.8% for erythromycin, 6.6% for gentamicin, and 46.3% for tetracycline. This study demonstrated that the majority of the Campylobacter isolates obtained from human samples in Korea were C. jejuni with ST-45 CC, which has been detected mainly in broilers worldwide, and all strains with new STs were uniformly resistant to enrofloxacin and tetracycline. This study indicates that broilers may be a breeding ground for bacteria as well as an important potential source of human campylobacteriosis.

Molecular Characterization, Antimicrobial Resistance and Caco-2 Cell Invasion Potential of Campylobacter jejuni/coli from Young Children with Diarrhea

“…25 In addition, GEN, CLI and CHL are also used for antibiotic therapy. Antimicrobial resistance rates were also high in C. coli (73.3%, 63.3% and 20%, respectively), which was similar with the results of another study in north China 39 and Korea, 38 suggesting the emergence of resistance to these antimicrobials. Therefore, establishment of integrated surveillance networks in China and other countries should be taken into consideration.…”

Identification of a Novel G2073A Mutation in 23S rRNA in Amphenicol-Selected Mutants of Campylobacter jejuni

“…Indeed, the CHL- and FFC-selected C. jejuni mutants carrying the G2073A mutation also showed elevated MICs to erythromycin (8 µg/mL), consistent with the finding in E. coli that the G2057A conferred cross resistance to chloramphenicol and erythromycin [23]. Interestingly in propionibacteria [32], Mycoplasma hominis [33], and Francisella tularensis [31], the same G2057A mutation was associated with erythromycin resistance, but not with resistance to 16-membered macrolides or chloramphenicol. It was postulated that the G2057 mutation in the 23S rRNA gene might lead to conformational changes in the binding sites of CHL and 14-membered macrolides, attenuating the affinity of these antimicrobials to the ribosome [52].…”

“…No chloramphenicol-resistant isolates were detected in studies performed in the United States [28], Spain [29], Japan [30], and Iran [31]. The chloramphenicol resistance detection rates were 0.8% in Korea [32]. In contrast to the low resistance rates in other countries, detection of chloramphenicol-resistant Campylobacter was high (37.5%) in Brazil [33].…”

High‐Level Ciprofloxacin‐Resistant Campylobacter jejuni Isolates Circulating in Humans and Animals in Incheon, Republic of Korea

“…Based on a national surveillance study in Korea, ciprofloxacin‐resistant C. jejuni strains were isolated from humans, accounting for more than 83.7% of total C. jejuni strains collected from 2008 to 2011 (KNIH, ), and this prevalence rate increased to 95.2% in this study. When combined with the previous reports in other Korean studies regarding the human isolates (24% for ciprofloxacin resistance during 2007–2009, 65% during 2005–2008 and 82.3% during 2007–2008) (Kim et al., ; Ku et al., ; Shin et al., ), it should be noted that the incidence of ciprofloxacin‐resistant C. jejuni isolates has increased rapidly and maintained at a high level over recent years.…”