Addition of Rifampicin to Bolton Broth to Inhibit Extended‐Spectrum β‐Lactamase‐Producing Escherichia coli for the Detection of Campylobacter

Abstract

Exponential growth of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in Campylobacter media has become a common problem for the detection of Campylobacter in chicken meats. We investigated the minimum inhibitory concentration of 40 ESBL-producing E. coli isolates from meats obtained from various countries against antibacterial agents in Bolton broth (cefoperazone, vancomycin, and trimethoprim). All ESBL-producing E. coli strains were resistant to cefoperazone and vancomycin, whereas 50% of them were resistant to trimethoprim and grew in Bolton broth. We found that 20 μg/mL of rifampicin inhibited the growth of trimethoprim-resistant E. coli strains. Hence, we added 20 μg/mL of rifampicin to Bolton broth to improve the isolation of Campylobacter from chicken carcass rinses. The isolation rate of Campylobacter was significantly higher in the modified broth (44 out of 58, 75.9%, P < 0.05) than in the normal broth (0 out of 58, 0%). Furthermore, the number of agar plates with non-Campylobacter spp. was much lower after enrichment in the modified broth (4 out of 58, 6.9%, P < 0.05) than in the normal broth (58 out of 58, 100%).

Metagenomic analysis of isolation methods of a targeted microbe, Campylobacter jejuni, from chicken feces with high microbial contamination

“…Using metagenomics alone, only the effects of the enrichment process on the isolation of Campylobacter can be evaluated; however, using a combination of metagenomics and culture-dependent tools enabled evaluation of the enrichment broth and selective media in isolating Campylobacter . Generally, the enrichment step had a greater effect on the isolation of microbes than did the selective media [13]. However, we found that selective media significantly affected target microbe isolation as well.…”

“…Changes in the overall microbial community and composition of specific microbes affecting the isolation of C. jejuni during isolation procedure have not been identified. Additionally, evaluation of the enrichment procedure using culture-based techniques, which greatly affects microbe isolation compared to selective procedures, is not possible [13]. Therefore, to accurately compare isolation methods of C. jejuni , studies based on metagenomics using next-generation sequencing are needed.…”

Research Note: A baseline survey of thermotolerant Campylobacter in retail chicken in southern Brazil

“…The resistance to cefoperazone would explain the spread of P. mirabilis on mCCD agar after enrichment in Bolton broth and the higher efficacy of Preston agar to inhibit contaminant strains sensitive to rifampicin. Owing to the high level of contaminants resistant to third-generation β-lactams used in Campylobacter -selective broth and agar culture media, the addition of rifampicin ( Chon et al., 2017 ), potassium clavulanate ( Moran et al., 2011 , Seliwiorstow et al., 2016 ), or triclosan ( Seliwiorstow et al., 2016 ) to Bolton broth was previously proposed to improve Campylobacter detection in chicken samples. Moreover, it has led to the recent revision of the ISO method for the analysis of samples with low Campylobacter numbers and a high level of background microflora, by introducing the enrichment of the test portions in Preston broth for 22 to 26 h ( Biesta-Peters et al., 2019 ).…”

“…An enrichment step is essential to analyze samples in which low numbers of Campylobacter cells are expected ( Sproston et al., 2014 ), yet extending the enrichment time might promote the growth of less fastidious antimicrobial-resistant bacteria ( Jasson et al., 2009 ). Moreover, the emergence of resistant nontarget bacteria, such as extended-spectrum β-lactamases ( ESBLs )–producing Escherichia coli , means the detection of Campylobacter using selective broth containing β-lactams might lead to underestimating its prevalence in chicken samples ( Jasson et al., 2009 , Chon et al., 2017 , Biesta-Peters et al., 2019 ). This study used both qualitative and quantitative bacteriological analyses to evaluate thermotolerant Campylobacter contamination in retail chicken in southern Brazil.…”

Bacteriophage-Mediated Modulation of Bacterial Competition during Selective Enrichment of Campylobacter

“…Particularly, extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli are resistant to cefoperazone, a 3rd generation cephalosporin drug used in Campylobacter -selective media, such as Bolton selective medium and modified charcoal-cefoperazone-deoxycholate (mCCD) agar. ESBL-producing E. coli are highly prevalent in chicken and interrupts Campylobacter isolation using current protocols ( 7 , 8 ), leading to a revision of the international standard for the detection and enumeration of Campylobacter ( 9 , 10 ). Our previous analysis of microbiome changes during the enrichment of Campylobacter in selective media demonstrated that ESBL-producing E. coli are more abundantly enriched than Campylobacter ( 11 , 12 ).…”