Genome sequence of a multidrug-resistant Campylobacter coli strain isolated from a newborn with severe diarrhea in Lebanon.

A multidrug-resistant (MDR) Campylobacter coli (C. coli) strain was isolated from a 2-month-old newborn who suffered from severe diarrhea in Lebanon. Here, whole-genome sequencing (WGS) analysis was deployed to determine the genetic basis of antimicrobial resistance and virulence in the C. coli isolate and to identify its epidemiological background (sequence type). The identity of the isolate was confirmed using API® Campy, MALDI-TOF, and 16S rRNA gene sequencing analysis. The antimicrobial susceptibility phenotype was determined using the disk diffusion assay. Our analysis showed that resistance to macrolide and quinolone was potentially associated with the presence of multiple point mutations in antibiotic targets on the chromosomal DNA. Furthermore, tetracycline and aminoglycoside resistance were encoded by genes on a pTet plasmid. The blaOXA-61, which is associated with beta-lactam resistance, was also detected in the C. coli genome. A set of 30 genes associated with the virulence in C. coli was detected using WGS analysis. MLST analysis classified the isolate as belonging to a new sequence type (ST-9588), a member of ST-828 complex which is mainly associated with humans and chickens. Taking together, this study provides the first WGS analysis of Campylobacter isolated from Lebanon. The detection of a variety of AMR and virulence determinants strongly emphasizes the need for studying the burden of Campylobacter in Lebanon and the Middle East and North Africa (MENA) region, where information on campylobacteriosis is scant.

Historical, current, and emerging tools for identification and serotyping of Shigella.

The Shigella genus includes serious foodborne disease etiologic agents, with 4 species and 54 serotypes. Identification at species and serotype levels is a crucial task in microbiological laboratories. Nevertheless, the genetic similarity between Shigella spp. and Escherichia coli challenges the correct identification and serotyping of Shigella spp., with subsequent negative repercussions on surveillance, epidemiological investigations, and selection of appropriate treatments. For this purpose, multiple techniques have been developed historically ranging from phenotype-based methods and single or multilocus molecular techniques to whole-genome sequencing (WGS). To facilitate the selection of the most relevant method, we herein provide a global overview of historical and emerging identification and serotyping techniques with a particular focus on the WGS-based approaches. This review highlights the excellent discriminatory power of WGS to more accurately elucidate the epidemiology of Shigella spp., disclose novel promising genomic targets for surveillance methods, and validate previous well-established methods.

Challenges in identification of enteroinvasive Escherichia coli and Shigella spp. in Lebanon.

This study aimed to evaluate the routine identification tools available in Lebanon for differentiation of Escherichia coli and Shigella spp. The identification of 43 isolates defined as Shigella spp. by Api 20E was accessed using MALDI-TOF, serological testing, duplex PCR targeting ipaH (present in Shigella spp. and enteroinvasive E. coli "EIEC") and lacY (found in E. coli including EIEC but not Shigella spp.) as well as gyrB gene sequencing. Antibiotic susceptibility was investigated as well as Shiga-toxin production. All isolates were identified as E. coli by MALDI-TOF while the PCR showed a disparate group of 26 EIEC, 11 Shigella spp., 5 E. coli and 1 inactive E. coli. However, the sequencing of gyrB gene, which was recently described as a suitable marker for distinguishing E. coli and Shigella spp., identified all isolates as E. coli. Antibiotic resistance was noticeable against ß-lactams, rifampicin, trimethoprim-sulfamethoxazole, gentamicin, and ciprofloxacin. The most common variants of beta-lactamase genes were blaTEM-1, blaCTX-M-15, and blaCTX-M-3. A great discordance between the used methods in identification was revealed herein. An accurate identification technique able to distinguish E. coli from Shigella spp. in routine laboratories is a pressing need in order to select the appropriate treatment and assess the epidemiology of these bacteria.