Search

Purpose: This study was aimed at investigating the occurrence and genetic mechanisms of resistance to ciprofloxacin, tetracycline and erythromycin in clinical isolates of Campylobacter jejuni recovered from human cases of acute gastroenteritis in Turkey., Methodology: MIC values of each antibiotic were determined with the epsilometer test (E-test). Resistance genes/mutations were first screened by PCR and analysed by subsequent DNA sequencing., Results: From a total of 152 C. jejuni isolates tested, 113 (74.3%), 38 (25%) and 9 (5.9%) were found to be resistant to ciprofloxacin, tetracycline and erythromycin, respectively. Sequence analysis of ciprofloxacin-resistant isolates showed that all resistant strains (n=113) carried Thr-86-Ile substition in the gyrA gene, which is the most frequently observed mutation in fluoroquinolone-resistant Campylobacter. All of the tetracycline-resistant isolates (n=38) carried the tetO gene. All of the erythromycin-resistant isolates (n=9) harboured the point mutation A2075G in the 23S rRNA gene, which is the most common mutation conferring macrolide resistance in C. jejuni., Conclusion: The phenotypic susceptibility testing results were found to agree well with those obtained by genetic detection methods for the C. jejuni isolates tested. The findings of this study showed a very high level of resistance to ciprofloxacin and to a lesser extent to tetracycline while resistance to erythromycin remained at a low level. Thus, erythromycin may be considered as the first choice for treatment of Campylobacter infections in this geographical region when indicated.

The aims of this study were to detect the frequency of isolation of thermophilic Campylobacter spp. from acute gastroenteritis cases by phenotypic and molecular methods and to evaluate the antibiotic susceptibilities of the isolates. A total of 3287 stool samples obtained from diarrheal patients who were admitted to Kayseri Training and Research Hospital, Kayseri, Turkey, between March 2010 - March 2011 and sent to the microbiology laboratory, were included in the study. Cefoperazone, amphotericin B and teicoplanin (CAT) supplemented Campylobacter Blood-free Selective Medium (modified CCDA-Preston, Oxoid CM739, UK) was used for the isolation of Campylobacter spp. The media inoculated with stool samples were incubated at 42°C microaerobically for 72 to 96 hours. The genus and species level identifications of the thermophilic Campylobacter spp. isolates defined by phenotypic tests were carried out with multiplex polymerase chain reaction (mPCR). Antibiotic susceptibilities of the isolates were detected by disc diffusion method and the results were evaluated according to the CLSI guidelines. The thermophilic Campylobacter spp. were isolated from 5.4% (179/3287) of the patients' stool samples. Of Campylobacter positive cases 71% (127/179) were children and 58% (104/179) were male. The prevalence rate was estimated as 7.5% (127/1683) for children and 3.2% (52/1604) for adults. Of the isolates, 146 (82%) were identified as C.jejuni, 24 (13%) were C.coli, 6 (3%) were C.lari and 3 (2%) were C.upsaliensis with phenotypic tests. By using mPCR, 152 (85%) and 27 (15%) of 179 isolates were identified as C.jejuni and C.coli, respectively. Three of the six isolates identified as C.lari by the phenotypic methods were identified as C.jejuni and the remaining three as C.coli by mPCR. Phenotypically identified three C.upsaliensis isolates were shown to be C.jejuni (n= 2) and C.coli (n= 1). On the other hand one C.coli isolate was found to be C.jejuni by mPCR. The rates of resistance of the isolates were 92.6% for trimethoprim-sulfamethoxazole, 79.5% for nalidixic acid, 75.6% for levofloxacin, 73.9% for ciprofloxacin, 40.3% for ampicillin, 35% for cefotaxime, 33.4% for piperacillin-tazobactam, 24% for tetracycline, 14.6% for clindamycin, 11.2% for amikacin and 6.3% for erythromycin. During the 13 months study period, the highest isolation rates were detected between March-June (mean rate 66%). Our data concerning the prevalence and antibiotic resistance rates revealed the significance of campylobacters in gastroenteritis cases. Therefore, specific microbiological isolation and identification methods should be applied in routine microbiology laboratories to investigate the presence of campylobacters in gastroenteritis etiology. Besides, determination of the antibiotic susceptibilities of the isolates on routine basis should be encouraged to help to guide the antimicrobial treatment approaches in case of gastroenteritis. The results of this study also indicated that phenotypic tests were adequate for the identification of campylobacters at the genus-level, however, for accurate identification at the species level and for reliable epidemiological data molecular analysis might be added to the detailed identification procedures.

The aims of this study were as follows: (i) to isolate Arcobacter spp. from the stool samples of patients with gastroenteritis; (ii) to identify them with molecular methods; (iii) to genotype them using enterobacterial repetitive intergenic consensus (ERIC)-PCR; and (iv) to determine their antibiotic susceptibilities. For the study, a total of 3287 diarrhoeal stool samples submitted to the Microbiology Laboratory of the Kayseri Training and Research Hospital, Kayseri, Turkey, between 2010 and 2011 were analysed. Campylobacter blood-free selective medium supplemented with cefoperazone, amphotericin B and teicoplanin was used for isolation. Medium inoculated with stool samples was incubated microaerobically at 37 °C for 72-96 h. Phenotypic tests, a genus-specific PCR and a multiplex PCR were used to identify the arcobacters, whilst ERIC-PCR was used for genotyping and the antibiotic susceptibilities of the isolates were detected by E-test. Arcobacter spp. were isolated from nine of the 3287 samples. These nine isolates were identified as Arcobacter butzleri and all showed different ERIC-PCR profiles. All nine isolates were resistant to ampicillin and susceptible to gentamicin, tetracycline, erythromycin and ciprofloxacin. As far as is known, this is the first study in which A. butzleri has been isolated from human acute gastrointestinal infections in Turkey. According to these results, it is recommended that, when investigating the aetiology of infections of the digestive system in humans, Arcobacter spp. be considered for inclusion. The results of this study should contribute to our knowledge related to A. butzleri infections in humans.